Re: function to get inverse color name?

[David Rogoff <david@therogoffs.com>]

Thanks Drew!


On Apr 24, 2014, at 6:44 AM, Drew Adams <drew.adams@oracle.com> wrote:

>> I'm doing a major overhaul of my emacs 24 init.el files.  I'm trying to
>> convert a lot of faces from dark to light to set up alternate themes.  I
>> know I can just invert everything with invert-all-faces, but I want to do
>> them individually and have the correct name.
>> 
>> Does anyone have a function that takes a named color (e.g. "Red") and
>> returns the inverse?  I guess it would convert the name to RRGGBB, subtract
>> each 8-bit value from 256, and then convert back to a name.
>> 
>> Thanks for any help and/or pointers to useful functions!
> 
> Library hexrgb.el has this (`hexrgb-complement') and many other such
> utility functions for colors.
> 
> Library palette.el provides a WYSIWYG color palette for working with
> colors.  In the palette, `~' picks the complement of the current color.
> 
> Both libraries are on Emacs Wiki and MELPA:
> http://www.emacswiki.org/emacs-en/download/hexrgb.el
> http://www.emacswiki.org/emacs-en/download/palette.el
> 
> You can see the color palette here:
> http://www.emacswiki.org/emacs/ColorPalette