Hi Joe: I'm only going on information given to me by persons who are much more knowledgeable than myself. I was actually told the emergers are a dark brown. I was told in the spring that the Olive Duns are a light olive color on the bottom, the part the fish sees. My own experience with fall olives is that they are gray-bodied duns. From what I've been learning in the past few posts olive spentwing spinners really don't exist. The reason I asked about olive spentwing spinners is because I can't recall every seeing them and I didn't want to overlook another way to fool the fish. I need all the help I can get. The only sure fire way to know size and color for sure is to look at a bug from the water you're fishing. I'm not very good with colors so I get second and third opinions. Colors can be subjective, too! Sorry I can't be more help.