I have always enjoyed butterflies of the family Pieridae. Their colors are mostly bright, cheery, and attractive overall. Even the "white" colored ones "pop" against a background of lush green or colored flowers. Within this family there are a number of species which seem to exhibit rather distinct divisions of color; reminiscent of 2 different butterfly species having been "spliced" together (so to speak). I can't say I've noticed it so much in other butterfly families but, I'm sure it exists. I just thought I would shed some light on some of these curious Pierids for your viewing pleasure. One thing of note is that this division of colors always seems to be an upper (forewings) vs. lower (hindwings) sort of thing. Not a left side (half) vs. right side (half) bi-lateral thing. Below, I present my 1st example from my own collection.
Catopsilia gorgophone (Female) Mt. Tamborine, Australia Mar.08.1975
So, with this species as well as others I will present; little if any of the lower hindwing color is carried over or "invades" the region of the forewings. Some species seem to have the bolder color on the hindwings whilst others still possess the bolder colors on the forewings (as you will see).
Finally, I present you with yet another twist to this casual observance of mine. Here, the bolder colors are present on the forewings rather than on the hindwings.
Hebomoia leucippe (Male) Moluccas and Peleng (Indonesia) In a friends collection...
So again, you can see this concept of "divisional" coloration which to me seems best illustrated amongst the Pierid butterflies. Other Pierid candidates which probably show this sort of thing are certain Colotis species of Africa (which come to mind at the moment).
This kinda makes me wonder if the food plant chemicals absorbed by the larvae (of certain species) are somehow re-directed during the pupal stage to a specific region during metamorphosis; i.e. (the wing pads) front or back. Thereby, giving some butterflies a look of "2 halves being better than one" !