I sat down at the vise last night to tie up some damsels and as I was picking through my marabou looking for the "right shade of green" it occurred to me that in lakes where I've seen a damsel migration I've often seen the nymphs in various shades from dark olive to almost chartreuse during the same event. Has anyone else noticed this and/or has anyone noticed an appreciable difference in effectiveness using different colors? I think Dave Whitlock had a two tone light & dark olive pattern, maybe this is the way to go and save some space in the fly box instead of having multiple patterns?