The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
but I do know that brachycentrid egg masses will stick to the old sealdry waders and the protein or whatever makes them stick leaves little pits in the wader.
From what I have seen, caddis egg sacs range through any color within the whites, tans, yellows, browns and greens depending on taxa. They change colors as they age over the hours they are around. I think they get darker with time.
My beloved wife took the time to wipe my breathables down using a damp washcloth, got rid of every last egg-sac.