Color, by itself, has less to do with reaction than it used to. Advancements have helped with that. However, sometimes the manufacturer needs to adjust the coverstock formula slightly in order to achieve their desired color.
For example, the Pink/Black Slingshot (if memory is correct) was actually the cover from the original Inferno because the pink turned out better with that formulation, which made that particular Slingshot a little better than the rest (in my opinion).
Perceived reaction versus actual reaction will always come into play. Some colors are seen by the eyes differently which can give the impression that "Ball A" hooks more than "Ball B", when in actuality they are the same (or any difference is barely distinguishable).