I would like to share some thoughts regarding colors on plastic like products.
Few weeks back I bought a digital piano, it was white, not black. I really wanted black but the store dealer told me "sorry there is only white", but he thought that white is better in the long run. He showed me 3 different black digital pianos (they were made out of some kind of plastic I believe) and 1 white (roughly the same age). You could definitely see that older black pianos colors started to fade, and seem washed out, there were not so brilliant as newer ones. The white one, stood out and kept its look quite well.
My point is, if you want something to keep looking good for some time, it might be that white color or the addition of white to the product will make it look better in the long run (my humble opinion).
I do agree that in HMD cases, the most important thing is the quality of the mechanism inside it and not the cover.
Just adding my 2 cents.