There is little doubt that anything that effects sunlight penetration into the water can effect fish coloration. Dye would certainly be included as it limits certain light wavelength penetration thus color response by BG. Here is a recent post on coloration and an older one on dye effects.

Blond BG
http://www.pondboss.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=20;t=004085


LAKE DYE Comparisons
http://www.pondboss.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=14;t=000167