The Colonel frequently refers to a "Georgia boy" with long sideburns, but never mentions his name. This could be a veiled reference to Elvis Presley, however Elvis was from Mississippi, not Georgia.
Fred Flintstone's singing voice is supplied by Duke Mitchell.
ABC Originally Broadcast This Episode In Black And White
"That Georgia boy" referenced by the Colonel is most likely Ray Charles who is from Georgia and was very famous at the time the episode aired (1961).
The Colonel is an obvious reference to Colonel Tom Parker the famous manager of Elvis.