Had you been a dedicated bass fisherman back in the '70, you would have read the articles in BassMaster magazine about color and what worked and why. The bass fishing suppliers spent millions of dollars doing scientific research, came out with the ColorLector to determine the best color to use depending of light, depth, water clarity, etc. The lure manufacturers came out with a bunch of really strange colors, which were supposed to catch fish. It never seem to grab the imagination of the bass fisherman like depth and temp instruments did. The results were decided color matters and changes based upon several variables.

BTW, blue and purple are two of the favorite colors for plastic worms among bass fishermen and have been for a long time. One famous fisherman, lure manufacturer, likes white plastic grubs on jigs and black when he runs out of white.