If the difference between black and white means anything to you, you'll see it here:
The crop on the left is taken from the famous Jack Beers photo of "Ruby" shooting Oswald. But, he's wearing light socks, while Ruby wore black socks. He didn't change his socks, did he?
He is wearing light socks, presumably grey, but Ruby was wearing jet black socks.
Also, Ruby wore a high-top functional work shoe, while the Garage Shooter wore a low-top dress shoe.
Different shoes and socks means they were different men.