There are three snakes which can meet that description that are found in Georgia. Two are small, and the other not so small. The small species are the Ringneck Snake(Diadophis punctatus), which has a characteristic orange or yellow ring behind its head, and the Red-Bellied Snake(Storeria occipitomaculata), both of which are generally less than a foot long. The larger species is the Red-Bellied Water Snake(Nerodia erythrogaster), which can grow up to four feet or more in length and is quite thick-bodied. Usually those are more brownish on top, but I have seen older specimens that looked grayish.
It is a ring necked snake. These snakes have trouble eating in captivity. I suggest if you don't want the snake to die that you release it back where you found it. Sorry.