Note: Scott's info applies to 1971 oad Runners or GTXs only. I believe John is taling about 1970 'cudas. Very different options. And the '71 RR-GTX had front and rear painted.
As Scott stated, your '71 RR-GTX bumper s could be V2 Tor-Red, J6 Sassy-Grass Green, F7 Sherwood Green, B5 True Blue, Y9 Tawny Gold, Y3 Curious Yellow.