Great pictures. It would be interesting to have a ventral perspective too. Are they lighter underneath and darker on top? In some species, the eyes are very prominent and in others, the eyes are more cryptic.
Most are lighter underneath except for the Drunella which can be just about as darkly colored ventrally as dorsally. The rest vary in color ventrally from white to a lighter color. The reason the eyes are more prominent in some species is that the males tend to have larger eyes (at least in mayflies).