I thought the early Model 601 rifles, the first AR-15s adopted by the US Air Force in 1959, had the green furniture. If I'm not mistaken, the brown was on the earliest AR-15 built in the late 1950s. Those two were kind of, sort of, more or less what I was going for with these two
My 601 clone is sporting a set of Green Brownells furniture. Mine is simply more subdued than yours. The light/camera also makes mine look much more Brown than it appears to the unaided eye.