+.SS Color Rendering
+The \fIcurses\fP library combines these inputs to produce the
+actual foreground and background colors shown on the screen:
+.bP
+per-character video attributes (e.g., via \fB\%waddch\fP),
+.bP
+the window attribute (e.g., by \fB\%wattrset\fP), and
+.bP
+the background character (e.g., \fB\%wbkgdset\fP).
+.PP
+Per-character and window attributes are usually set by a parameter containing
+video attributes including a color pair value.
+Some functions such as \fB\%wattr_set\fP use a separate parameter which
+is the color pair number.
+.PP
+The background character is a special case: it includes a character value,
+just as if it were passed to \fB\%waddch\fP.
+.PP
+The \fIcurses\fP library does the actual work of combining these color
+pairs in an internal function called from \fB\%waddch\fP:
+.bP
+If the parameter passed to \fB\%waddch\fP is \fIblank\fP,
+and it uses the special color pair 0,
+.RS
+.bP
+\fIcurses\fP next checks the window attribute.
+.bP
+If the window attribute does not use color pair 0,
+\fIcurses\fP uses the color pair from the window attribute.
+.bP
+Otherwise, \fIcurses\fP uses the background character.
+.RE
+.bP
+If the parameter passed to \fB\%waddch\fP is \fInot blank\fP,
+or it does not use the special color pair 0,
+\fIcurses\fP prefers the color pair from the parameter,
+if it is nonzero.
+Otherwise, it tries the window attribute next, and finally the
+background character.
+.PP
+Some \fIcurses\fP functions such as \fB\%wprintw\fP call \fB\%waddch\fP.
+Those do not combine its parameter with a color pair.
+Consequently those calls use only the window attribute or
+the background character.
+.SH CONSTANTS
+In \fB\%<curses.h>\fP the following macros are defined.
+These are the standard colors (ISO-6429).
+\fIcurses\fP also assumes that \fB\%COLOR_BLACK\fP is the default
+background color for all terminals.
+.PP
+.nf
+ \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.
+There are no standard names for those additional colors.
+.SH VARIABLES
+.SS COLORS
+is initialized by \fB\%start_color\fP to the maximum number of colors
+the terminal can support.
+.SS COLOR_PAIRS
+is initialized by \fB\%start_color\fP to the maximum number of color pairs
+the terminal can support.
+.SH FUNCTIONS
+.SS start_color
+The \fB\%start_color\fP routine requires no arguments.