Colors module documentation

[Debraheem]

By user request,

See https://lists.mesastar.org/pipermail/mesa-users/2026-February/015791.html

Perhaps we can update the colors documentation with the latest details from Nial's website so these two sources are consistent. User's tend to look inside the MESA docs when using MESA, so it would be a good idea to duplicate the information from NIal's website into the Colors module documentation, which remains quite limited to date.

[nialljmiller]

This issue is addressed in pr #929. colors module and custom_colors test suite have had their README updated to better reflect that seen on https://nialljmiller.com/projects/MESA_CC/custom_coloUrs.html. I have not added the images or videos from my website because of GitLFS.

Cheers,
Niall

[Debraheem]

Thanks Niall!