Ouch! Good luck with predicting how a baby corn snake is going to look, as far as color is concerned when it reaches adulthood. I had to keep a lot of babies every year just so I could see if they were heading in the right direction I was hoping for. Even knowing what the parents look like, it's still pretty much a crap shoot concerning variation among babies.
So I would suggest having a general idea in mind of what you want the color to be in what you get, but expect a large margin of variation and don't get your hopes up too high for something really specific. I often told people who wanted something very specific that they would need to go to a reptile show and hope to find exactly what they want in an adult by LOOKING at adults for sale and seeing it with their own two eyes while it was right in front of them. Even photographs can sometimes be misleading, as can be just the type of light the snakes are in. It is actually rare that a baby looks like the gem that they can potentially turn into.
When I used to do shows, I would use lights that were as close to the spectrum of sunlight as I could find, as that normally allowed the best colors of the animals to show through. The same animals under fluorescent or regular 2700K incandescent bulbs would look shabby in comparison. So even buying an animal in person, it might look completely different when you get it home and look at it under different lights.
Not as easy as it seemed, now is it?
