Here is an interesting one. My tiger lavender line is old and the most recessive it ever hid was Toyger Caramel. I know nothing is "proof" unless it is 100% sure but I thought the info could still help.
Editing to say I went back and found the last Caramel is 6 generations back and I have had almost 50 boxes since that have all been Tiger Lavender or a more dominate fur. Still wont know for sure without opening the box if it hides Caramel but that still would knock off 6 furs. The Tiger would knock off over 20.