@cindex colors on text-only terminals
Emacs can display color on text-only terminals, starting with version
-21. These terminals support only a small number of colors, and the
-computer uses small integers to select colors on the terminal. This
+21. These terminals usually support only a small number of colors, and
+the computer uses small integers to select colors on the terminal. This
means that the computer cannot reliably tell what the selected color
looks like; instead, you have to inform your application which small
integers correspond to which colors. However, Emacs does know the
standard set of colors and will try to use them automatically.
+ The functions described in this section control how terminal colors
+are used by Emacs.
+
@cindex rgb value
Several of these functions use or return @dfn{rgb values}. An rgb
value is a list of three integers, which give the amount of red, the
selected frame's terminal; @pxref{Input Focus}). At present, though,
the @var{display} argument has no effect.
+@defun tty-display-color-cells &optional display
+This function returns the number of distinct colors supported for
+@var{display}.
+@end defun
+
@defun tty-color-define name number &optional rgb display
@tindex tty-color-define
This function associates the color name @var{name} with