Like, one cannot ungreen nipples with certain pills, or ungreen facial hair & voice with different pills. Right?

Correct. Other methods are needed to fix those things.

Not thinking so much of undoing what has been done by such pill, but more so the effects the first time around (I.e. not to ungreen something that has been greened with pills, but ungreen something that was already green naturally)

Doesn't really matter either way (although surgical changes of A -> B -> A are a lot harder than A->B or B->A).

Removing anti-green skin organs? Isn’t green skin an effect of hormones, which said pills play on? Unless you’re talking about something else here (or I’m uninformed, which is very possible). On a similar note, there’s one pill to “remove” purple skin and one pill for getting green skin, no? Pretty sure I’ve heard of something like that somewhere (or not. Idk.)

Gonna just break the metaphor here: If you have testes (or ovaries I assume) removed and don't take any sort of supplemental hormones, it can have a negative impacts on bone density long-term.

On a similar note, there’s one pill to “remove” purple skin and one pill for getting green skin, no? Pretty sure I’ve heard of something like that somewhere (or not. Idk.)

Yeah. Two different regimes. But the meme seems intentionally vague about what green skin is a metaphor for, so I tried to make my comment apply both ways >.<

Guess it’d be easier to find a “green skin 101” and properly learn stuff, but I reckon I’d just be inundated with “chroma key 101” instead. Still, am always interested in learning more (usually in video format, cause I’m lazy to read sometimes). I mean, I already have a trans creator (who talks trans stuff) on my video feed. Maybe it’s a matter of searching for the older content to learn more.

Also, not using a poorly defined metaphor to talk about it would help be more clear about things. I don't have any videos to suggest unfortunately.

Anyway, thanks for the information and for your time!

No worries.