I think I have cracked the code. Please keep in mind that a color mutation does not always occur when mixing these color combinations. However, when they do these are the resulting color combinations. Might need some fine tuning bc sometimes it's hard to determine the colors especially on dinos with fur.
Red + Pink = Gold
Black + Black = Purple
Brown + Brown = White
Orange + White = Green
Orange + Brown = Blue
Brown + Black = Tan
Light Brown + Gray/Black = Red.
Please let u