For some reason, Japanese artists seem to not realise that pubic hair changes colour along with head hair. I've seen many hentai pictures of girls with a hair colour that's quite natural (like ginger, blond or light brown) but have jet black pubes.
Presumably because (a) Japanese people only have one hair colour so this sort of variance is quite literally foreign to them and (b) pretty much the only time they'll see naked foreigners is in US porn and therefore they'll be looking at women with bleached blonde hair mostly.
OK, you can get variation sometimes. But the fact is that with the vast majority of people all body hair matches up but in Japanese artwork, 99% of the time, they have pubes that are dark brown or black regardless of their head hair colour. A possible, and I think very likely, reason for that is because Japanese people often see foreigner's head hair but not pubic hair and so assume that it's just the head hair that's a different colour.
not teclo its not like that the hair tends to be a lot darker outside the "head" ofc its not like light green into black But light green into dark green maybe
For one thing, maybe it's just an optical illusion, but I see the pubes in this pic as a dark green.
For another, it's easier to draw pubes in black. Other colors, you have to do the lines and then add color; with brown or black, you only need to do the lines.