Kenn M. Ligas produced a very nice 3 ring binder of fly patterns. In it, he identified the color of each, based on the Borger Color System and the use of Scintilla dubbing material.
At the end of he book, he includes two pages of small samples of the colors which are named and numbered based on the Borger Color System.
Page 1 of the samples pages
Page 2
In addition to the variations of color due to the stage of emergence, location of the watershed, etc. (pointed out by Silver Creek, above), there is the relatively significant difference between the color of the dubbing when dry and when wet...................
The other nice thing about the Ligas notebook is that he he has information on the Eastern version of the insect and the Western version.......
This is a typical page on the Eastern Stonefly...............You will note that he provides color differentiation for the parts of the insect.