I just bought my rig and it was partually filled with gas/oil. Well the guy I bought it from showed me the oil he uses and it is from his dealer which sells it in bulk. The color was DARK BLUE. Well I have ALOT of supertec wally world oil stored up LIGHT BLUE. Will it be ok to mix these two types of oils togethor?? It worrys me that one is DARK blue and one is LIGHT blue?? 