Board Thread:New on Pretty Cure Wiki/@comment-25034020-20181022151836/@comment-37117761-20181109235843

Here's my theory. The bad guys want to crowd the entire universe with their light, creating a universe where everyone is forever happy. The good guys realize that sadness is necessary to be truly happy, and that the stars can't shine brightly without a pitch-black sky. Thus, the heroes are darkness-themed, and the villains are light-themed.