[antonfire]

> Some women are tetrachromats with an extra colour sense, while men are more likely to have red/green colour blindness.

If I'm not mistaken, red/green color blindness is more common in men because it's caused my a mutation on the X chromosome (which men tend to have fewer of). I would guess a similar thing about tetrachromacy.

So those are probably unrelated to color-perception changes due to exogenous estrogen.