EPISTASIS in Cornsnakes?

Epistasis is a phenomenon that consists of the effect of one gene being dependent on the presence of one or more “modifier genes” (genetic background).

I was watching Youtube videos about Genetics the other day and stumbled upon this phenomenon. Generally, a third phenotype is generated when two separate genes are paired.

Is there such thing in cornsnakes? I was thinking of the PurpleX wherein the Lavender color is much different when paired to some genes (personally, i dont know PurpleX, i just read some posts here).