#lang s-exp "../../lang/base.rkt" (provide (except-out [struct-out color] color make-color) [rename-out [-color make-color] [-color color]]) (define-struct color (red green blue alpha) #:extra-constructor-name make-color) (define -color (case-lambda [(r g b) (color r g b 255)] [(r g b a) (color r g b a)]))