Contrary to popular belief, MOST (I say most because there are some intergrades, though the requirements for keeping them are still the same)cornsnake morphs are the same species...just different colors. Since they are the same species, their needs are the same. An Anerythristic cornsnake needs the same conditions as an Amelanistic cornsake, because they are both of the same species, just different skin pigmentations and/or pattern of markings.
So...40-60% humidity.