In Northern Lake Michigan we have very bright golden carp, others that are almost completely black and then every shade between gold and black. I often tell people that whenever they have the option, cast to the brightest colored carp.
There is no question that the brighter the carp the better their eyes, therefore those are the best carp at seeing and running down your fly. They seem to be more alert overall and unfortunately are the first to spook from our presence. A tailing bright carp would never allow us to drift the boat on top of them but we do it all the time with dark fish.
Bright carp seem to cruise and hunt more often while their dark cousins spend much of their time mudding around in silty areas. To characterize body form the bright fish have a streamlined shape and are strong swimmers and as you might guess are the best fighters. In contrast, the dark carp are often short and round with the darkest ones having bulging eyes like the fish you see in tanks. Sometimes we take shot after shot, watching the fly go within inches of a dark tailing carp and still cannot get its attention.
Remember to go for the gold whenever you get the choice.
