I should have known I would have gotten a tonne of questions about my "don't ask" statement in the write-up for the Poison Ivy custom. Rather than email everyone back individually, I'll just save time an post the theory here.
I'm toying with the notion that the plant growth overriding her animal biology is centred in her womb, thus that area of her body is where it's strongest and further out she's less green. It also just helps her not look so flat, as a single-shaded green skin tends to do.
