Wishlist.

Hi,

Some time ago I wrote some integration with lcms2 in the interest of
replacing tty-color-approximate, color-distance, etc. with superior
(more perceptually uniform) color metrics.  This would presumably
improve Emacs' color picking on smaller color palettes (e.g. 256 color
term) and potentially provide access to many useful color-related
functions in Lisp---not to discount color.el.

I am not sure how this might be added--perhaps in its own .c file and
exposing a feature?

Attached is a patch splicing lcms2 CIE DE2000 into color-distance.
I don't know what x_alloc_nearest_color_1 does but I apparently patched
that as well.

Also attached is a small module with CIE DE2000 and CAM02-UCS color
distance functions.