I probably keep things too simple, but it's easier for me to keep everything to a minimum. I put more emphasis on the type of lure than I do color.
I generally only buy one color (sometimes 2) of each specific lure. All my craws, senkos, tubes and trds are GP, all flukes are white, all speed worms and frogs are black, etc. My jigs and chatterbaits are bluegill color or white. Same applies for hard baits, but I don't use them as often.