Are you sure about that?
I've been trying to research that and haven't had a lot of luck finding original source shots clearly showing the button color on BOTH sides. It hasn't been overly obvious to me whether they're both red or not.
I'm just curious what you found. Thanks.
Graflex buttons, which is what the original saber was made from, are red. In ANH the top button was red and the bottom button area had a "glass eye" which is really just a clear looking button lens. In ESB both buttons are red.