Inserting and removing the cartridge from the GameBoy a bunch of times might just fix the problem you're experiencing.
(This reminds me - I've been meaning to make an animated gif showing a cartridge being inserted and removed from a GameBoy an infinite amount of times.)
But I play many other Gameboys that are a bunch of different colors.
I guess I have almost a dozen different colored Gameboys if I include all the different painted ones and I like/use them all so its kind of difficult to answer "What colour is you're gameboy?"
I have White, Orange, and Pink backlights and they all look fantastic!
http://store.kitsch-bent.com/product/ledx3 (this LEDx3 backlight in pink is easier on the eyes than every other pink backlight that I've seen, its kind of a peach color)
But, this is the next backlight that I'm personally getting -