The first sentence of the description of colored is “This tag is used for images and animations that feature color”, which implies to me that the tag is used on all images that have color.

But then the rest of the description and some of the aliases seem to imply that this tag is only used for images that are colored versions of already existent black/white images.

Which one is it?

I can’t find a separate tag that covers either of those definitions ( color edit is close, but it requires that the coloration was done by someone other than the original artist), so it seems like the ‘colored’ tag is currently being used for both.

Should ‘colored’ be used for that first definition, with ‘colorized’/‘coloration’ (which are currently aliased to ‘colored’) be used instead for the second definition?

Here are the correct wiki links.
colored
color edit

Making "colored" apply to every polychromatic image would essentially just make it the negation of monochrome, at which point it really doesn't have any value for searching.

usernamesweretaken said:
The first sentence of the description of Meta: colored is “This tag is used for images and animations that feature color”, which implies to me that the tag is used on all images that have color.

But then the rest of the description and some of the aliases seem to imply that this tag is only used for images that are colored versions of already existent black/white images.

Which one is it?

It should be the former, and is often used to mean that, although it was originally conceptualized as the latter. We don't otherwise tag "versions" of images, beyond third-party edits (which is used to help indicate what was added by a third party and not done by or in collaboration with the original artist); we just tag what the given version has irrespective of what other versions may or may not have in relation to it. Shaded applies to images which have shading, even if there isn't an unshaded version, sketch applies to a sketch, regardless of there being a non-sketch version somewhere, etc. It would get confusing otherwise when dealing with images that have other versions that aren't posted here, are private or behind paywalls (e.g. a perk that gives access to sketches or other in-progress versions, when only the completed version is made freely available), and/or when multiple versions have the same attribute, e.g. a sketch version, line_art version, a flat color version, and a fully shaded version).

But as Lafcadio says, the colored tag specifically doesn't have much utility as a catch-all for all colored images. It has been discussed to invalidate it, but no decisions have been made.

lafcadio said:
Here are the correct wiki links.
colored
color edit

Making "colored" apply to every polychromatic image would essentially just make it the negation of monochrome, at which point it really doesn't have any value for searching.

That’s fair. So maybe just modify the description of colored so that it more clearly only applies to colorized versions of monochrome images? (although in that case I think it would be more clear for the official tag to be ‘colorized’ with ‘colored’ aliased to that, instead of the other way around)