Partway through "Saban's Power Rangers," the latest feature-film version of the long-running television series, a bit of marketing-speak sneaks into the script. The story, such as it is, consists of five ethnically diverse teenagers in a California town who discover color-coded medallions that transform them into superheroes. A robot named Alpha 5, with the jocular voice of Bill Hader, sums it up neatly: "Different colors!