I don’t know the color of the mayfly larvae. I know they are brownish when they float to the top of the water before hatching into mayflies. I also know that many people will tell you that the fishing sucks after a big hatch. While that may hold true for panfish and forage fish that feed on fishflies it most certainly does not hold true for preditor fish like walleyes. One of my most memorable walleye episodes happened several years ago when I was fishing a closing dam in a narrow slough. There had been a huge fishfly hatch the night before and the trees on either end of this closing dam were covered black with fishflies. The shad were feeding heavily on these fishflies and the walleye were feeding heavily on the shad as well as my crankbait.
<—-Agree with Eyehunter. Some of the best bass fishing is during and right after the hatch. The only bad part is you get all kinds of regirgitated mayflies all over your boat….
If you want to try to match the hatch, my best colors are usually a copperish color. I make and use mayfly rigs with either gold or copper beads. These can be absolutely killer.
I also don’t mind throwing a shad or pearl colored crank right at the pods of bugs.