Fly color, like most things, is cyclical. A few years ago, UV material was all the rage, before that bright colors, and of course dull tones as well. There are several adages relating to color: bright day, dull fly, bright day: bright fly. Neither makes any sense over the long term. You just have to make a best estimate as to what the fish are taking.
"Match the hatch" is probably the best rule to follow. If the hatch is green body Caddis, use that, etc.
"Match the hatch" is probably the best rule to follow. If the hatch is green body Caddis, use that, etc.