@ThatGuyThere
Yep. It gets used as an appeal to nostalgia, and a lazy one at that. Four Color is supposed to mean 'classic superheroes' half the time it's used. OP is using the term, too. I really think he needs to be a lot more specific, or that will bite him on the ass, later. Maybe pick a particular superhero, or team, or at least a publisher, and specify an era, with examples. Something like, "A 1950s Superman feel." or "In the spirit of 1960s Avengers" or whatever.
Otherwise, they're going to get the kitchen sink. And since players always trend towards wanting their characters to stand out, they will begin to outweird one another. 'Four Color' games invariably seem to degenerate into some kind of LSD Supertrip with flying dragons and anthropomorphic nazi penguin cyborgs. It just takes time for the players to slowly push the boundaries.
@Runescryer , be specific.