it's showing green as a character for me now.
I'm going to assume Cogs just fixed it today somehow since https://booru.allthefallen.moe/post_versions?search%5Bchanged_tags%5D=doujima_nanako shows him editing pics with her today.
Normally you can't edit the category of a tag with 400+ entries but maybe Cogs has unlocked the special mod route to save our tags?
If so I might have to bother him as I remember others which need that. Efforts to put together a complete list didn't really solidify...
is one pair that came to mind as ones I'm not able to categorize via prefixing due to their high populations