Yup, Ken's right.
All the offspring breeding an Amel to Anery will look absolutely normal in appearance, but will carry the genes for both amel & anery (which combined makes snow).
If you breed the double het babies to each other once they are of age, you'll get a mix of
* normal babies that may be het for both, one or neither of the traits.
* Anerythristics which may or may not be het for Amel
* Amelanistics which may or may not be het for Anery
* Snows (displaying both the Amel & Anery traits).
As for the exact chances of what you'll get (and a 1 in 16 chance doesn't mean that if you produce 16 eggs one of them will definitely be a snow, it means that EACH EGG has a 1 in 16 chance of being a snow. You might breed double hets together and get ALL snows, or you could get ALL anery or amel or normals) I'm not sure right now. It's late, my head's hurting, and I forgot where I put my calculator ;P