I think you make a good point. A lure needs to look like a prey item, and color is important, especially when the fish are keyed in on a certain bait.
But you also answered your own question, too, when you mentioned one bait out of a batch working better than the rest. The difference in the action of that one bait sets it apart from the others.
This is what I consider when I'm trying to figure out what paint scheme to put on a lure.
There are three retrieve features that I think are key to getting bit.
The first is being able to achieve a reaction strike, by "surprising" a bass, so it reacts without thinking.
The second is wounded prey, where an erratic action or retrieve mimics a wounded bait fish.
The third is the passive feeding, casual retrieve, when a lure gives off no negative cues that will turn a bass away, and simulates a baitfish well enough to convince a bass that it's an easy meal.
Reaction strikes happen no matter what color you're throwing. A bass will react with a strike if it's surprised, and you lure seems to be escaping. They can't help themselves, it's hard wired into their brains. Bright colors that catch their eye are important here, like chartruese and silver flash.
The second is why baits get bit in off color water, at night, and even in muddy water. The vibration given off by a lure makes a bass aware that there's something struggling nearby. Again, in off colored water, it helps to have clearly visible lures, so the chartruese and blue, which provide both visibility and contrast, are my go to choices. The cleared the water, the more important natural lure colors become. My lakes in SoCal are seldom really dirty, so I lean toward match the hatch color schemes a lot, and hope my lures look erratic enough to attract a feeding response in a bass.
The third is really a clear water deal, and calls for the most realistic paint scheme you can muster. A bass has the enire retrieve to scope out your lure, and decide if it wants to eat it. I just read a guy's post on how he got bit on a trout colored swimbait at Clear Lake, even though there are no trout there, only hitch. A bass will follow anything that swims right, to see if it's a meal worth eating. That's the reason a 180 degree turn is so important on jointed swimbaits. They get followed a lot, and that 180 turn can trigger a reaction bite from a fish that was just curious. But it only works sometimes, and only if the lure is realistic enough, in both action and appearance, to get the bass interested in the first place.
This is what I think about when I decide how to finish a lure. But first I try to make a lure that has an action that will attract a bass in the first place.
It's like in golf. You've got to get it to the hole. 100% of putts that are short don't go in.