SO. I just found out from tag group:art that we have "color theme" tags. So here's a summary of what I now know of the general color tags:

Generic/related

• restricted_palette
• monochrome
• sepia
• greyscale
• spot_color
• cold_colors
• warm_colors
• color_swatch
• chiaroscuro (see also backlit)

X_and_X

• White
• black_and_white
• black_and_white_and_red
• blue_and_white
• red_and_white
• brown_and_white
• green_and_white
• pink_and_white
• orange_and_white
• yellow_and_white
• Black
• black_and_red
• black_and_blue
• black_and_grey (!?)

Themes (with extras not listed on the wiki page)

• dark_theme

• black_theme
• grey_theme (!)
• blue_theme
• teal_theme
• cyan_theme
• brown_theme
• beige_theme
• tan_theme
• hazel_theme (?!)
• green_theme
• green_and_white_theme
• grey_theme
• orange_theme
• pink_theme
• purple_theme
• red_theme
• white_theme
• green_and_white_theme
• yellow_theme
• gold_theme
• jaws_theme

Clearly there is significant redundancy (e.g. black_and_grey = greyscale) and almost no implications at all. Not to mention that what the "theme" tags are supposed to be is vague to me at best.

I don't care enough to bother with clogging the forum with a bunch of alias/implications proposals, but it seems that some sort of cleanup or at least a good discussion would be a good idea.