Actually I have a few like this. There seems to be something lurking in a gene pool I have that causes a general lightening effect in whatever other genetic traits it mixes with. Unfortunately it seems rather unpredictable, at least to my poor tired brain. And for the most part, I get only females. I do have one breeding sized male, but he didn't fare very well last year in the pairings with him.
I tend to get oddities like this every year. I think it is only after you are breeding a large number of animals of the same species that you can begin to grasp the diabolical nature and frequency of spontaneous genetic mutations. You have to wonder how many things like this pop up in the wild as a single individual that luck just doesn't favor them surviving to produce more of them. Or perhaps the trait itself that they carry is just not favorable to help them survive. I would imagine a dayglow purple cornsnake wouldn't last 48 hours in the wild.
But it sure is interesting watching the results in our own little personal test tube collections.