The tag implication #9267 two-sided_hair -> multicolored_hair has been rejected.

Reason: The two sides are generally distinguished by strongly contrasting colors, so more than one color is always present. Theoretically artists could achieve the same effect with two different shades of the same color, but I have not seen a single case of this. I assume black and white are considered colors for this purpose.

I considered implying two-tone_hair instead but ruled it out because there are a few cases where additional streaks or more complex coloration is present, e.g. https://www.pixiv.net/member_illust.php?mode=medium&illust_id=73052552

EDIT: This tag implication is pending automatic rejection in 5 days.

EDIT: This tag implication has been rejected because it was not approved within 60 days.

EDIT: The tag implication two-sided_hair -> multicolored_hair (forum #158456) has been rejected by @DanbooruBot.

Two-sided_hair isn't a very good name for this tag, IMHO. My first impression, just from reading the tag's name, was that it was meant for hair divided into two colors to the left and right, like post #269405, post #938878, post #3140466, or post #3515503. Tags with misleading names are ripe for misuse, so it would be better to replace this tag with something less ambiguous.

I'll submit peekaboo_highlights as a potential replacement, since it appears to be the most common name for this hairstyle and Google Images seems to confirm this. If there's an even more descriptive tag, though, perhaps we should go with that instead.

The google images don't quite match the concept since they are a layer of highlights between a higher and lower layer. Two-sided highlights are visible from the front, i.e. there's only two layers.

But I agree that the name is suboptimal and should be replaced if a better alternative is found. Pixiv calls it inner color but that doesn't quite fit with danbooru taxonomy.

Would "double-sided" be clearer?

Did a little googling, and it seems that peekaboo_highlights could cover it, but the term refers to two different but similar ideas. One is it refers to dying the bottom layer of hair (the idea we want tagged here) and the other is having various different colors of highlights throughout the hair so when the hair is styled you'd have the various colors peeking out.

I'd probably go with trying to use a name that is closer to what the Japanese are calling it so something like "colored_inner_hair", "colored_under_hair", "dyed_under_hair", etc. Googling seems to suggest one common way of referring to it in English is calling it "dyed hair underneath."

Dyed doesn't work since you never know with anime hair colors.

colored_inner_hair could work. It feels a little off since it's not like the outer side doesn't have color, but close enough.

The bulk update request #2064 is active.

mass update two-sided_hair -> colored_inner_hair
create implication colored_inner_hair -> multicolored_hair

Reason: Based on suggestions from iridescent slime and NWF Renim

EDIT: This bulk update request is pending automatic rejection in 5 days.

EDIT: The bulk update request #2064 (forum #158634) has been approved by @Hillside_Moose.

i was looking for a tag like this a while ago and couldn't find it. "inner color" was one of the first things i looked for.

i agree that colored is a weird phrasing, since it essentially implies dying. inner_hair_color might be better, if not at least two keystrokes shorter.

I kind of took the "colored" as a double-edged sword. I agree that it implies dying but I felt it also implied that the color was different from the rest of the hair. I didn't feel that "inner_hair_color" had that same innate implication that there is a difference between the color of the inner hair and the outer hair, and didn't really want to have to go with a longer "different_inner_hair_color" as the name.

edit: Although "different_inner_hair" could also be a possibility, though not sure how well that will do without wording that it is specifically for color.

If we want to get all technical we could call it orientable_hair.
Orientable is a mathematical term for surfaces with distinct sides (as opposed to e.g. a moebius strip which only has one side). And for it to work with hair it would also have to be sheet-like.
But I don't think anyone would learn about that by typing some close match into the search box, you could only find it by example.

NWF_Renim said:

I didn't feel that "inner_hair_color" had that same innate implication that there is a difference between the color of the inner hair and the outer hair

seems pretty implicit to me. why else would it be tagged if it wasn't different in some way? for example, streaked hair isn't different color streaked hair.

that said, either inner color or colored inner is fine. technical accuracy isn't as important as being intuitive and searchable, and both those terms are already connected to the popular japanese term.

This tag implication is pending automatic rejection in 5 days.

This tag implication has been rejected because it was not approved within 60 days.

The tag implication two-sided_hair -> multicolored_hair (forum #158456) has been rejected by @DanbooruBot.

This bulk update request is pending automatic rejection in 5 days.

The bulk update request #2064 (forum #158634) has been approved by @Hillside_Moose.

Quick note that I did ElectricSheep's BUR.