My take on color is this:
I think it depends on the location you are fishing in relation to the sun. Case In point
One day me and my old fishing bud, were out on his crawdad in a good largemouth bass lake. I was fishing the left side of the boat (deeper water) and he the right (or shoreline) as we rounded a mainlake point we started hitting them good. He was throwing a red shad ribbontail powerworm, and I had green pumpkin with brown centerline zipperworm, what was odd was I was hitting them regularly, but he wasnt getting hit unless he cast to a spot with no shade.
Now red shad is well known to he and i as a good sunny day color. As this had been proven over and over to us. And the green pumpkin just a good all around color. So it seemed as though things were in line and correct,.. what was apparently odd was his "hits" came on the shoreline facing side of the weeds, (in the weeds shade) and mine from the deeper weedline facing the sun.
Being perplexed we switched casting directions, and the "hits" stopped abruptly. That red shad should have produced in the suns rays, but didnt, and my green pumpkin should have produced as well,...we changed sides again and we were back "on them".
Does color matter? In some instances,... I say yeah it does. And I beleive that its the correlation of the suns direction, to the backgound of the "covers color",.,... Meaning the green of the weeds and the brownish color of the shorelines bottom.
Now, we had also determined other days, that any color we threw worked, no matter where, when, direction, conditions,... etc.
So, in summary?,.. some days I say color does matter, and some it doesnt, My theory is, the suns direction "may" play part in color selection as long as the water clarity, and cover present, provides the conditions condusive to allow such. Is there a "key" set in stone? I dont think so, as nothing is in bass fishing as we all know. But Im sure,... that sometimes color does matter. We proved it to ourselves.
Keep ya line wet!