For the most part I agree with you. But I also do believe in a few staple colors for certain water conditions. For example muddy water black and for clear brown. Every lake I've fished from MO to MI this has been pretty consistent for me. Throw a few greens like watermelon, and green pumpkin, white and you need nothing else imo. Those are the basic colors of natural colors in most bodies of water.
There is one thing I have not figured out yet though. In muddy water slower presentations like plastics and jigs the majority vote is black or variations of it. But why on reaction baits do most anglers opt for bright colors? That is just one I cant figure out. Can a fish really see a difference in muddy water beyond a foot. I sure cant see the lure beyond a foot.