Jim, both the Colt 1878 and 1883 originally had black and white Damascus like this 1878 and 1883 below. I took the photos under an incandescent light so color is not exact, but they both appear to be very black and white.
Beautiful two barrel set by the way. Had one of these years ago. IMO the 83s were sone of the best designed and built box action doubles of that era. Jim