Coloring

The basic way to color the grid is by making a function that takes in a distance and puts out a color.

An more challenging way to color the grid is by figuring out which depot is closest and then coloring all points by a color assigned to the closest depot.

You can choose your own coloring function or use mine. I suggest you change this once you start making images and would like to adjust the way they look.

(define (color-select n)
  (make-color (limit (- 255 (* 50 n)))
              0
              (limit (* 100 n))))
(define (limit n)
  (max 0 (min 255 (real->int n))))