(define (start-simon n)
  (initialize-game n)
  (define (rdm) (random n))
  (set-state-colors! master (build-list n (lambda (x) (cond
                                                       [(= (rdm) 0) 'red]
                                                       [(= (rdm) 1) 'blue]
                                                       [(= (rdm) 2) 'yellow]
                                                       [else 'green])))))