A generator of infinite contiguously-good-looking colors

colouri.js

;(function(global, undefined) {
  'use strict';
  var Colouri = function() {
    this.color = '1d9caf';
  };
  global.Colouri    = Colouri;
  Colouri.prototype = (function() {
    /**
      * Private
      */
    var hue = function(color) {
      color   = (color.indexOf(0) == '#') ? color.substr(1) : color;
      var rgb = color.match(/([A-Za-z0-9]{2})/g)
        .map(function(e) { return parseInt(e, 16) }),
        r   = rgb[0] || 0,
        g   = rgb[1] || 0,
        b   = rgb[2] || 0,
        $r  = r / 255,
        $g  = g / 255,
        $b  = b / 255,
        max = [$r, $g, $b].sort(function(a, b) {
          return b - a;
        }).shift(),
        min = [$r, $g, $b].sort(function(a, b) {
          return a - b;
        }).shift(),
        delta = max - min;
        switch(max) {
          case $r:
            return 60 * ((($g - $b) / delta) % 6);
            break;
          case $g:
            return 60 * ((($b - $r) / delta) + 2);
            break;
          case $b:
            return 60 * ((($r - $g) / delta) + 4);
            break;
        }
      };
      /**
        * Public
        */
      return {
        Constructor: Colouri,
        generate:   function () {
          var currentHue = hue(this.color),
              origHue    = currentHue,
              queue      = [];
          return function() {
              if (currentHue + 20 >= 360) {
                currentHue = ((currentHue + 20) - 360) + 0;
              } else {
                currentHue += 20;
              }
              if (!(queue.length % 3)) {
                queue.push((currentHue - 180 < 0) ? (360 - currentHue - 180) : currentHue - 180);
              }
              queue.push(currentHue);
              if (!(queue.length % 4)) {
                  currentHue = origHue = queue.shift();
              }
              return currentHue;
          };
        }
      };
  })();
 
})(this);
/*
var color     = new Colouri(),
    generator = color.generate(),
    map       = Array.prototype.map;

map.call(document.getElementsByTagName('div'), function(e) {
    e.style.background = 'hsl(' + Math.floor ( generator() ) + ', 70%, ' + Math.floor((Math.random() * (50 - 20)) + 20) + '% )';
});
*/