Color differences between DD Crankbaits and deep soft plastics.

[Bob Smith]

Anybody ever give any thoughts as to why we typically catch bass on brighter colored crankbaits in Deep water, while at the same time we typically catch bass out of the same area on more of your natural or subdued colors like watermelon, pumpkin seed, purple, green pumpkin, Black, Brown and the like, for our soft plastic presentations (knowing there are and will be exceptions when chartreuse, white, pearl, pink and methyolate work better. That is the subject for another "why" question.)?
My personal theory is that the crankbaits mimic baitfish type forage and the soft plastic mimic worms, leeches and crustaceans. Hence the color differences. If there are some different theories, it would be interesting to hear them.