Bought the Color-C-lector when it first came out (1970's ? ) .... then upgraded to the Combo-C-lector ( color/temp/pH) when that came along. Seemed like most of the time that I went fishing & used it, it would tell me to use a color that I was already using & had confidence in ..... Blue/chartreuse !!
The biggest "problem" with them, then & now, IMHO .. is that you need to know how deep the fish are BEFORE you put the probe down to test for what color(s) are most visible at that depth. If I know how deep the fish are ... I can pretty well guess what colors to use, since I'm imitating the color of the foodsource that the fish would most likely be feeding on, at that depth.
IMHO - it's part gimick & part science. IF it was a major factor in the catching of fish, you'd see the boats of the Pro's decked out with one & them using it !! And I'm not talking about just those Pro's sponsored by the company ... but, all/most of them !!

... pappy