I suppose you are asking what is the difference between a "regular" Red Empress and a "super" Red Empress? You can't tell. A "super" is supposedly a line bred improved strain that is supposed to be reliably colorful.
A dominant male can color up some at 3". The color does not mean anything, thou it is good that he is showing potential for nice red and blue.
Really, the natural Red Empress male is a very beautiful fish when colored up. The only problem is that quality of fish gets worse after 3 or 4 generations in captivity. Some of the fish in the hobby are hard to tell if they are pure or not.