Fishermen belief does have a lot to do with what we use....but their is also alittle science!
We do know that ALL Baitfish have a gold iridescence that predator fish can key on when the sun is out or UV light is available...We also know that Chartreuse takes on a Golden hue in stained water...that's the main reason that I use a Chartreuse Nibblet in the daytime.
Smell is a trigger under certain circumstance, then you also have alot of other baitfish colors which can attract predators...white bellies, orange coloration, hues of different colors in different water.
Or you can just have different contrasting colors that can attract the attention of predator fish and elicit a strike.