gistfile1.clj

(defn rgb-distance-squared
  "Euclidean distance squared between two rgb values"
     [[r1 g1 b1] [r2 g2 b2]]
     (let [r (- r1 r2)
	   g (- g1 g2)
	   b (- b1 b2)]
       (+
	(* r r)
	(* g g)
	(* b b))))

(def key-colours
     {[224 41 224] :purple
      [24 180 46] :green
      [12 129 245] :blue
      [254 232 23] :yellow
      [233 233 233] :white
      [245 27 55] :red
      [231 119 41] :orange
      })

(defn rgb-to-key-colour
  "Find colour in colour map closest to the supplied [r g b] triple"
  [rgb-triple colour-map]
  (colour-map
   (apply min-key (partial rgb-distance-squared rgb-triple) (keys colour-map))))

(rgb-to-key-colour [255 0 0] key-colours)
:red