ncurses 6.3 - patch 20220709

[ncurses.git] / man / curs_color.3x

diff --git a/man/curs_color.3x b/man/curs_color.3x
index b3521cb1b425423a47881de341b3ae4837e37d8f..46d50cc92f998500e10fea9079256ec8a131571d 100644 (file)
--- a/man/curs_color.3x
+++ b/man/curs_color.3x
@@ -1,5 +1,5 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright 2018-2019,2020 Thomas E. Dickey                                *
+.\" Copyright 2018-2021,2022 Thomas E. Dickey                                *

 .\" Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *


@@ -27,7 +27,7 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: curs_color.3x,v 1.62 2020/02/02 23:34:34 tom Exp $
+.\" $Id: curs_color.3x,v 1.68 2022/02/12 20:06:41 tom Exp $

 .TH curs_color 3X ""
 .ie \n(.g .ds `` \(lq
 .el       .ds `` ``
 .TH curs_color 3X ""
 .ie \n(.g .ds `` \(lq
 .el       .ds `` ``


@@ -41,81 +41,81 @@
 .na
 .hy 0
 .SH NAME
 .na
 .hy 0
 .SH NAME

-\fBstart_color\fR,
-\fBhas_colors\fR,
-\fBcan_change_color\fR,
-\fBinit_pair\fR,
-\fBinit_color\fR,
-\fBinit_extended_pair\fR,
-\fBinit_extended_color\fR,
-\fBcolor_content\fR,
-\fBpair_content\fR,
-\fBextended_color_content\fR,
-\fBextended_pair_content\fR,
-\fBreset_color_pairs\fR,
-\fBCOLOR_PAIR\fR,
-\fBPAIR_NUMBER\fR \- \fBcurses\fR color manipulation routines
+\fBstart_color\fP,
+\fBhas_colors\fP,
+\fBcan_change_color\fP,
+\fBinit_pair\fP,
+\fBinit_color\fP,
+\fBinit_extended_pair\fP,
+\fBinit_extended_color\fP,
+\fBcolor_content\fP,
+\fBpair_content\fP,
+\fBextended_color_content\fP,
+\fBextended_pair_content\fP,
+\fBreset_color_pairs\fP,
+\fBCOLOR_PAIR\fP,
+\fBPAIR_NUMBER\fP \- \fBcurses\fP color manipulation routines

 .ad
 .hy
 .SH SYNOPSIS
 .ad
 .hy
 .SH SYNOPSIS

-\fB#include <curses.h>\fR
+\fB#include <curses.h>\fP

 .sp
 .sp

-\fBint start_color(void);\fR
+\fBint start_color(void);\fP

 .sp
 .sp

-\fBbool has_colors(void);\fR
+\fBbool has_colors(void);\fP

 .br
 .br

-\fBbool can_change_color(void);\fR
+\fBbool can_change_color(void);\fP

 .sp
 .sp

-\fBint init_pair(short pair, short f, short b);\fR
+\fBint init_pair(short \fIpair\fB, short \fIf\fB, short \fIb\fB);\fR

 .br
 .br

-\fBint init_color(short color, short r, short g, short b);\fR
+\fBint init_color(short \fIcolor\fB, short \fIr\fB, short \fIg\fB, short \fIb\fB);\fR

 .br
 /* extensions */
 .br
 .br
 /* extensions */
 .br

-\fBint init_extended_pair(int pair, int f, int b);\fR
+\fBint init_extended_pair(int \fIpair\fB, int \fIf\fB, int \fIb\fB);\fR

 .br
 .br

-\fBint init_extended_color(int color, int r, int g, int b);\fR
+\fBint init_extended_color(int \fIcolor\fB, int \fIr\fB, int \fIg\fB, int \fIb\fB);\fR

 .sp
 .sp

-\fBint color_content(short color, short *r, short *g, short *b);\fR
+\fBint color_content(short \fIcolor\fB, short *\fIr\fB, short *\fIg\fB, short *\fIb\fB);\fR

 .br
 .br

-\fBint pair_content(short pair, short *f, short *b);\fR
+\fBint pair_content(short \fIpair\fB, short *\fIf\fB, short *\fIb\fB);\fR

 .br
 /* extensions */
 .br
 .br
 /* extensions */
 .br

-\fBint extended_color_content(int color, int *r, int *g, int *b);\fR
+\fBint extended_color_content(int \fIcolor\fB, int *\fIr\fB, int *\fIg\fB, int *\fIb\fB);\fR

 .br
 .br

-\fBint extended_pair_content(int pair, int *f, int *b);\fR
+\fBint extended_pair_content(int \fIpair\fB, int *\fIf\fB, int *\fIb\fB);\fR

 .sp
 /* extensions */
 .br
 .sp
 /* extensions */
 .br

-\fBvoid reset_color_pairs(void);\fR
+\fBvoid reset_color_pairs(void);\fP

 .sp
 .sp

-\fBint COLOR_PAIR(int n);\fR
+\fBint COLOR_PAIR(int \fIn\fB);\fR

 .br
 .br

-\fBPAIR_NUMBER(\fR\fIattrs\fR\fB);\fP
+\fBPAIR_NUMBER(\fIattrs\fB);\fR

 .br
 .SH DESCRIPTION
 .SS Overview
 .br
 .SH DESCRIPTION
 .SS Overview

-\fBcurses\fR supports color attributes on terminals with that capability.
-To use these routines \fBstart_color\fR must be called, usually right after
-\fBinitscr\fR.
+\fBcurses\fP supports color attributes on terminals with that capability.
+To use these routines \fBstart_color\fP must be called, usually right after
+\fBinitscr\fP.

 Colors are always used in pairs (referred to as color-pairs).
 A color-pair consists of a foreground color (for characters) and a background
 color (for the blank field on which the characters are displayed).
 Colors are always used in pairs (referred to as color-pairs).
 A color-pair consists of a foreground color (for characters) and a background
 color (for the blank field on which the characters are displayed).

-A programmer initializes a color-pair with the routine \fBinit_pair\fR.
-After it has been initialized, \fBCOLOR_PAIR\fR(\fIn\fR)
+A programmer initializes a color-pair with the routine \fBinit_pair\fP.
+After it has been initialized, \fBCOLOR_PAIR\fP(\fIn\fP)

 can be used to convert the pair to a video attribute.
 .PP
 If a terminal is capable of redefining colors, the programmer can use the
 can be used to convert the pair to a video attribute.
 .PP
 If a terminal is capable of redefining colors, the programmer can use the

-routine \fBinit_color\fR to change the definition of a color.
-The routines \fBhas_colors\fR and \fBcan_change_color\fR
-return \fBTRUE\fR or \fBFALSE\fR,
+routine \fBinit_color\fP to change the definition of a color.
+The routines \fBhas_colors\fP and \fBcan_change_color\fP
+return \fBTRUE\fP or \fBFALSE\fP,

 depending on whether the terminal has color capabilities and whether the
 programmer can change the colors.
 depending on whether the terminal has color capabilities and whether the
 programmer can change the colors.

-The routine \fBcolor_content\fR allows a
+The routine \fBcolor_content\fP allows a

 programmer to extract the amounts of red, green, and blue components in an
 initialized color.
 programmer to extract the amounts of red, green, and blue components in an
 initialized color.

-The routine \fBpair_content\fR allows a programmer to find
+The routine \fBpair_content\fP allows a programmer to find

 out how a given color-pair is currently defined.
 .SS Color Rendering
 The \fBcurses\fP library combines these inputs to produce the
 out how a given color-pair is currently defined.
 .SS Color Rendering
 The \fBcurses\fP library combines these inputs to produce the


@@ -163,20 +163,20 @@ Consequently those calls use only the window attribute or
 the background character.
 .SH CONSTANTS
 .PP
 the background character.
 .SH CONSTANTS
 .PP

-In \fB<curses.h>\fR the following macros are defined.
+In \fB<curses.h>\fP the following macros are defined.

 These are the standard colors (ISO-6429).
 These are the standard colors (ISO-6429).

-\fBcurses\fR also assumes that \fBCOLOR_BLACK\fR is the default
+\fBcurses\fP also assumes that \fBCOLOR_BLACK\fP is the default

 background color for all terminals.
 .PP
 .nf
 background color for all terminals.
 .PP
 .nf

-      \fBCOLOR_BLACK\fR
-      \fBCOLOR_RED\fR
-      \fBCOLOR_GREEN\fR
-      \fBCOLOR_YELLOW\fR
-      \fBCOLOR_BLUE\fR
-      \fBCOLOR_MAGENTA\fR
-      \fBCOLOR_CYAN\fR
-      \fBCOLOR_WHITE\fR
+      \fBCOLOR_BLACK\fP
+      \fBCOLOR_RED\fP
+      \fBCOLOR_GREEN\fP
+      \fBCOLOR_YELLOW\fP
+      \fBCOLOR_BLUE\fP
+      \fBCOLOR_MAGENTA\fP
+      \fBCOLOR_CYAN\fP
+      \fBCOLOR_WHITE\fP

 .fi
 .PP
 Some terminals support more than the eight (8) \*(``ANSI\*('' colors.
 .fi
 .PP
 Some terminals support more than the eight (8) \*(``ANSI\*('' colors.


@@ -190,14 +190,14 @@ is initialized by \fBstart_color\fP to the maximum number of color pairs
 the terminal can support.
 .SH FUNCTIONS
 .SS start_color
 the terminal can support.
 .SH FUNCTIONS
 .SS start_color

-The \fBstart_color\fR routine requires no arguments.
+The \fBstart_color\fP routine requires no arguments.

 It must be called if the programmer wants to use colors, and before any other
 color manipulation routine is called.
 It must be called if the programmer wants to use colors, and before any other
 color manipulation routine is called.

-It is good practice to call this routine right after \fBinitscr\fR.
-\fBstart_color\fR does this:
+It is good practice to call this routine right after \fBinitscr\fP.
+\fBstart_color\fP does this:

 .bP
 .bP

-It initializes two global variables, \fBCOLORS\fR and
-\fBCOLOR_PAIRS\fR (respectively defining the maximum number of colors
+It initializes two global variables, \fBCOLORS\fP and
+\fBCOLOR_PAIRS\fP (respectively defining the maximum number of colors

 and color-pairs the terminal can support).
 .bP
 It initializes the special color pair \fB0\fP to the default foreground
 and color-pairs the terminal can support).
 .bP
 It initializes the special color pair \fB0\fP to the default foreground


@@ -237,8 +237,8 @@ along with the terminal's color.
 These limits apply to color values and color pairs.
 Values outside these limits are not legal, and may result in a runtime error:
 .bP
 These limits apply to color values and color pairs.
 Values outside these limits are not legal, and may result in a runtime error:
 .bP

-\fBCOLORS\fP corresponds to the terminal database's \fBmax_colors\fR capability,
-(see \fBterminfo\fR(\*n)).
+\fBCOLORS\fP corresponds to the terminal database's \fBmax_colors\fP capability,
+(see \fBterminfo\fP(\*n)).

 .bP
 color values are expected to be in the range \fB0\fP to \fBCOLORS\-1\fP,
 inclusive (including \fB0\fP and \fBCOLORS\-1\fP).
 .bP
 color values are expected to be in the range \fB0\fP to \fBCOLORS\-1\fP,
 inclusive (including \fB0\fP and \fBCOLORS\-1\fP).


@@ -248,7 +248,7 @@ to denote the \fIdefault color\fP (see \fBuse_default_colors\fP(3X)).
 .bP
 \fBCOLOR_PAIRS\fP corresponds to
 the terminal database's \fBmax_pairs\fP capability,
 .bP
 \fBCOLOR_PAIRS\fP corresponds to
 the terminal database's \fBmax_pairs\fP capability,

-(see \fBterminfo\fR(\*n)).
+(see \fBterminfo\fP(\*n)).

 .bP
 legal color pair values are in the range \fB1\fP to \fBCOLOR_PAIRS\-1\fP,
 inclusive.
 .bP
 legal color pair values are in the range \fB1\fP to \fBCOLOR_PAIRS\-1\fP,
 inclusive.


@@ -260,22 +260,22 @@ but is actually whatever the terminal implements before color is initialized.
 It cannot be modified by the application.
 .SS has_colors
 .PP
 It cannot be modified by the application.
 .SS has_colors
 .PP

-The \fBhas_colors\fR routine requires no arguments.
-It returns \fBTRUE\fR if
-the terminal can manipulate colors; otherwise, it returns \fBFALSE\fR.
+The \fBhas_colors\fP routine requires no arguments.
+It returns \fBTRUE\fP if
+the terminal can manipulate colors; otherwise, it returns \fBFALSE\fP.

 This routine facilitates writing terminal-independent programs.
 For example, a programmer can use it to decide
 whether to use color or some other video attribute.
 .SS can_change_color
 .PP
 This routine facilitates writing terminal-independent programs.
 For example, a programmer can use it to decide
 whether to use color or some other video attribute.
 .SS can_change_color
 .PP

-The \fBcan_change_color\fR routine requires no arguments.
-It returns \fBTRUE\fR if the terminal supports colors
+The \fBcan_change_color\fP routine requires no arguments.
+It returns \fBTRUE\fP if the terminal supports colors

 and can change their definitions;
 and can change their definitions;

-other, it returns \fBFALSE\fR.
+other, it returns \fBFALSE\fP.

 This routine facilitates writing terminal-independent programs.
 .SS init_pair
 .PP
 This routine facilitates writing terminal-independent programs.
 .SS init_pair
 .PP

-The \fBinit_pair\fR routine changes the definition of a color-pair.
+The \fBinit_pair\fP routine changes the definition of a color-pair.

 It takes three arguments:
 the number of the color-pair to be changed, the foreground
 color number, and the background color number.
 It takes three arguments:
 the number of the color-pair to be changed, the foreground
 color number, and the background color number.


@@ -293,9 +293,9 @@ the screen is refreshed and all occurrences of that color-pair
 are changed to the new definition.
 .PP
 As an extension, ncurses allows you to set color pair \fB0\fP via
 are changed to the new definition.
 .PP
 As an extension, ncurses allows you to set color pair \fB0\fP via

-the \fBassume_default_colors\fR(3X) routine, or to specify the use of
-default colors (color number \fB\-1\fR) if you first invoke the
-\fBuse_default_colors\fR(3X) routine.
+the \fBassume_default_colors\fP(3X) routine, or to specify the use of
+default colors (color number \fB\-1\fP) if you first invoke the
+\fBuse_default_colors\fP(3X) routine.

 .SS init_extended_pair
 .PP
 Because \fBinit_pair\fP uses signed \fBshort\fPs for its parameters,
 .SS init_extended_pair
 .PP
 Because \fBinit_pair\fP uses signed \fBshort\fPs for its parameters,


@@ -306,19 +306,19 @@ for the color-pair and color-value,
 allowing a larger number of colors to be supported.
 .SS init_color
 .PP
 allowing a larger number of colors to be supported.
 .SS init_color
 .PP

-The \fBinit_color\fR routine changes the definition of a color.
+The \fBinit_color\fP routine changes the definition of a color.

 It takes four arguments:
 the number of the color to be changed followed by three RGB values
 (for the amounts of red, green, and blue components).
 .bP
 The first argument must be a legal color value;
 default colors are not allowed here.
 It takes four arguments:
 the number of the color to be changed followed by three RGB values
 (for the amounts of red, green, and blue components).
 .bP
 The first argument must be a legal color value;
 default colors are not allowed here.

-(See the section \fBColors\fR for the default color index.)
+(See the section \fBColors\fP for the default color index.)

 .bP
 Each of the last three arguments
 must be a value in the range \fB0\fP through \fB1000\fP.
 .PP
 .bP
 Each of the last three arguments
 must be a value in the range \fB0\fP through \fB1000\fP.
 .PP

-When \fBinit_color\fR is used, all
+When \fBinit_color\fP is used, all

 occurrences of that color on the screen immediately change to the new
 definition.
 .SS init_extended_color
 occurrences of that color on the screen immediately change to the new
 definition.
 .SS init_extended_color


@@ -332,7 +332,7 @@ for setting the red, green, and blue components,
 allowing a larger number of colors to be supported.
 .SS color_content
 .PP
 allowing a larger number of colors to be supported.
 .SS color_content
 .PP

-The \fBcolor_content\fR routine gives programmers a way to find the intensity
+The \fBcolor_content\fP routine gives programmers a way to find the intensity

 of the red, green, and blue (RGB) components in a color.
 It requires four arguments: the color number, and three addresses
 of \fBshort\fRs for storing
 of the red, green, and blue (RGB) components in a color.
 It requires four arguments: the color number, and three addresses
 of \fBshort\fRs for storing


@@ -357,18 +357,18 @@ for returning the red, green, and blue components,
 allowing a larger number of colors to be supported.
 .SS pair_content
 .PP
 allowing a larger number of colors to be supported.
 .SS pair_content
 .PP

-The \fBpair_content\fR routine allows programmers to find out what colors a
+The \fBpair_content\fP routine allows programmers to find out what colors a

 given color-pair consists of.
 It requires three arguments: the color-pair
 number, and two addresses of \fBshort\fRs for storing the foreground and the
 background color numbers.
 .bP
 The first argument must be a legal color value,
 given color-pair consists of.
 It requires three arguments: the color-pair
 number, and two addresses of \fBshort\fRs for storing the foreground and the
 background color numbers.
 .bP
 The first argument must be a legal color value,

-i.e., in the range \fB1\fP through \fBCOLOR_PAIRS\-1\fR, inclusive.
+i.e., in the range \fB1\fP through \fBCOLOR_PAIRS\-1\fP, inclusive.

 .bP
 The values that are stored at the addresses pointed
 to by the second and third arguments are in the
 .bP
 The values that are stored at the addresses pointed
 to by the second and third arguments are in the

-range \fB0\fP through \fBCOLORS\fR, inclusive.
+range \fB0\fP through \fBCOLORS\fP, inclusive.

 .SS extended_pair_content
 .PP
 Because \fBpair_content\fP uses signed \fBshort\fPs for its parameters,
 .SS extended_pair_content
 .PP
 Because \fBpair_content\fP uses signed \fBshort\fPs for its parameters,


@@ -385,27 +385,27 @@ It also touches the current- and standard-screens, allowing an application to
 switch color palettes rapidly.
 .SS PAIR_NUMBER
 .PP
 switch color palettes rapidly.
 .SS PAIR_NUMBER
 .PP

-\fBPAIR_NUMBER(\fR\fIattrs\fR) extracts the color
+\fBPAIR_NUMBER(\fIattrs\fR) extracts the color

 value from its \fIattrs\fP parameter and returns it as a color pair number.
 .SS COLOR_PAIR
 value from its \fIattrs\fP parameter and returns it as a color pair number.
 .SS COLOR_PAIR

-Its inverse \fBCOLOR_PAIR(\fR\fIn\fR\fB)\fR converts a color pair number
+Its inverse \fBCOLOR_PAIR(\fIn\fB)\fR converts a color pair number

 to an attribute.
 Attributes can hold color pairs in the range 0 to 255.
 If you need a color pair larger than that, you must use functions
 such as \fBattr_set\fP (which pass the color pair as a separate parameter)
 rather than the legacy functions such as \fBattrset\fP.
 .SH RETURN VALUE
 to an attribute.
 Attributes can hold color pairs in the range 0 to 255.
 If you need a color pair larger than that, you must use functions
 such as \fBattr_set\fP (which pass the color pair as a separate parameter)
 rather than the legacy functions such as \fBattrset\fP.
 .SH RETURN VALUE

-The routines \fBcan_change_color\fR and \fBhas_colors\fR return \fBTRUE\fR
-or \fBFALSE\fR.
+The routines \fBcan_change_color\fP and \fBhas_colors\fP return \fBTRUE\fP
+or \fBFALSE\fP.

 .PP
 .PP

-All other routines return the integer \fBERR\fR upon failure and an \fBOK\fR
+All other routines return the integer \fBERR\fP upon failure and an \fBOK\fP

 (SVr4 specifies only \*(``an integer value
 (SVr4 specifies only \*(``an integer value

-other than \fBERR\fR\*('') upon successful completion.
+other than \fBERR\fP\*('') upon successful completion.

 .PP
 X/Open defines no error conditions.
 SVr4 does document some error conditions which apply in general:
 .bP
 .PP
 X/Open defines no error conditions.
 SVr4 does document some error conditions which apply in general:
 .bP

-This implementation will return \fBERR\fR on attempts to
+This implementation will return \fBERR\fP on attempts to

 use color values outside the range \fB0\fP to \fBCOLORS\fP\-1
 (except for the default colors extension),
 or use color pairs outside the range \fB0\fP to \fBCOLOR_PAIRS\-1\fP.
 use color values outside the range \fB0\fP to \fBCOLORS\fP\-1
 (except for the default colors extension),
 or use color pairs outside the range \fB0\fP to \fBCOLOR_PAIRS\-1\fP.


@@ -422,7 +422,7 @@ if \fBstart_color\fP was not called.
 SVr4 does much the same, except that
 it returns \fBERR\fP from \fBpair_content\fP if the pair was not initialized
 using \fBinit_pairs\fP
 SVr4 does much the same, except that
 it returns \fBERR\fP from \fBpair_content\fP if the pair was not initialized
 using \fBinit_pairs\fP

-and 
+and

 it returns \fBERR\fP from \fBcolor_content\fP
 if the terminal does not support changing colors.
 .IP
 it returns \fBERR\fP from \fBcolor_content\fP
 if the terminal does not support changing colors.
 .IP


@@ -440,10 +440,10 @@ from the terminal description.
 returns an error if the color table cannot be allocated.
 .RE
 .SH NOTES
 returns an error if the color table cannot be allocated.
 .RE
 .SH NOTES

-In the \fBncurses\fR implementation, there is a separate color activation flag,
+In the \fBncurses\fP implementation, there is a separate color activation flag,

 color palette, color pairs table,
 and associated \fBCOLORS\fP and \fBCOLOR_PAIRS\fP counts
 color palette, color pairs table,
 and associated \fBCOLORS\fP and \fBCOLOR_PAIRS\fP counts

-for each screen; the \fBstart_color\fR function only affects the current
+for each screen; the \fBstart_color\fP function only affects the current

 screen.
 The SVr4/XSI interface is not really designed with this in mind, and
 historical implementations may use a single shared color palette.
 screen.
 The SVr4/XSI interface is not really designed with this in mind, and
 historical implementations may use a single shared color palette.


@@ -452,13 +452,13 @@ Setting an implicit background color via a color pair affects only
 character cells that a character write operation explicitly touches.
 To change
 the background color used when parts of a window are blanked by erasing or
 character cells that a character write operation explicitly touches.
 To change
 the background color used when parts of a window are blanked by erasing or

-scrolling operations, see \fBcurs_bkgd\fR(3X).
+scrolling operations, see \fBcurs_bkgd\fP(3X).

 .PP
 Several caveats apply on older x86 machines
 (e.g., i386, i486) with VGA-compatible graphics:
 .bP
 COLOR_YELLOW is actually brown.
 .PP
 Several caveats apply on older x86 machines
 (e.g., i386, i486) with VGA-compatible graphics:
 .bP
 COLOR_YELLOW is actually brown.

-To get yellow, use COLOR_YELLOW combined with the \fBA_BOLD\fR attribute.
+To get yellow, use COLOR_YELLOW combined with the \fBA_BOLD\fP attribute.

 .bP
 The A_BLINK attribute should in theory cause the background to go bright.
 This often fails to work, and even some cards for which it mostly works
 .bP
 The A_BLINK attribute should in theory cause the background to go bright.
 This often fails to work, and even some cards for which it mostly works


@@ -467,17 +467,65 @@ Paradise and compatibles) do the wrong thing when you try to set a bright
 \*(``yellow\*('' background (you get a blinking yellow foreground instead).
 .bP
 Color RGB values are not settable.
 \*(``yellow\*('' background (you get a blinking yellow foreground instead).
 .bP
 Color RGB values are not settable.

+.SH HISTORY
+.PP
+SVr3.2 introduced color support to curses in 1987.
+.PP
+SVr4 made internal changes,
+e.g., moving the storage for the color state
+from \fBSP\fP (the \fBSCREEN\fP structure)
+to \fBcur_term\fP (the \fBTERMINAL\fP structure),
+but provided the same set of library functions.
+.PP
+SVr4 curses limits the number of color pairs to 64,
+reserving color pair zero (0) as the terminal's initial uncolored state.
+This limit arises because the color pair information is a bitfield
+in the \fBchtype\fP data type (denoted by \fBA_COLOR\fP).
+.PP
+Other implementations of curses had different limits:
+.bP
+PCCurses (1987-1990) provided for only eight (8) colors.
+.bP
+PDCurses (1992-present) inherited the 8-color limitation from PCCurses,
+but changed this to 256 in version 2.5 (2001),
+along with changing \fBchtype\fP from 16-bits to 32-bits.
+.bP
+X/Open Curses (1992-present)
+added a new structure \fBcchar_t\fP to store the character,
+attributes and color-pair values, allowing increased range of color-pairs.
+Both color-pairs and color-values used a signed \fBshort\fP,
+limiting values to 15 bits.
+.bP
+ncurses (1992-present) uses eight bits for \fBA_COLOR\fP in \fBchtype\fP values.
+.IP
+Version 5.3 provided a wide-character interface (2002),
+but left color-pairs as part of the attributes-field.
+.IP
+Since version 6 (2015),
+ncurses uses a separate \fBint\fP for color-pairs in the \fBcchar_t\fP values.
+When those color-pair values fit in 8 bits,
+ncurses allows color-pairs to be manipulated
+via the functions using \fBchtype\fP values.
+.bP
+NetBSD curses used 6 bits from
+2000 (when colors were first supported) until 2004.
+At that point, NetBSD changed to use 10 bits.
+As of 2021, that size is unchanged.
+Like ncurses before version 6,
+the NetBSD color-pair information is stored in
+the attributes field of \fBcchar_t\fP, limiting the number of color-pairs
+by the size of the bitfield.

 .SH PORTABILITY
 This implementation satisfies XSI Curses's minimum maximums
 .SH PORTABILITY
 This implementation satisfies XSI Curses's minimum maximums

-for \fBCOLORS\fR and \fBCOLOR_PAIRS\fR.
+for \fBCOLORS\fP and \fBCOLOR_PAIRS\fP.

 .PP
 The \fBinit_pair\fP routine accepts negative values of foreground
 .PP
 The \fBinit_pair\fP routine accepts negative values of foreground

-and background color to support the \fBuse_default_colors\fR(3X) extension,
+and background color to support the \fBuse_default_colors\fP(3X) extension,

 but only if that routine has been first invoked.
 .PP
 but only if that routine has been first invoked.
 .PP

-The assumption that \fBCOLOR_BLACK\fR is the default
+The assumption that \fBCOLOR_BLACK\fP is the default

 background color for all terminals can be modified using the
 background color for all terminals can be modified using the

-\fBassume_default_colors\fR(3X) extension.
+\fBassume_default_colors\fP(3X) extension.

 .PP
 This implementation checks the pointers,
 e.g., for the values returned by
 .PP
 This implementation checks the pointers,
 e.g., for the values returned by


@@ -495,8 +543,8 @@ allowing applications to use larger color- and pair-numbers.
 .PP
 The \fBreset_color_pairs\fP function is an extension of ncurses.
 .SH SEE ALSO
 .PP
 The \fBreset_color_pairs\fP function is an extension of ncurses.
 .SH SEE ALSO

-\fBcurses\fR(3X),
-\fBcurs_initscr\fR(3X),
-\fBcurs_attr\fR(3X),
-\fBcurs_variables\fR(3X),
-\fBdefault_colors\fR(3X)
+\fBcurses\fP(3X),
+\fBcurs_initscr\fP(3X),
+\fBcurs_attr\fP(3X),
+\fBcurs_variables\fP(3X),
+\fBdefault_colors\fP(3X)