Added a way of ensuring correct versions between server and client

server/public/assets/js/helpers.js

@@ -100,6 +100,33 @@ var Helper = {
 		} : null;
 	},
 
+	hslToRgb: function(h, s, l) {
+  var r, g, b;
+	console.log(h, s, l);
+
+  if (s == 0) {
+    r = g = b = l; // achromatic
+  } else {
+    function hue2rgb(p, q, t) {
+      if (t < 0) t += 1;
+      if (t > 1) t -= 1;
+      if (t < 1/6) return p + (q - p) * 6 * t;
+      if (t < 1/2) return q;
+      if (t < 2/3) return p + (q - p) * (2/3 - t) * 6;
+      return p;
+    }
+
+    var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+    var p = 2 * l - q;
+
+    r = hue2rgb(p, q, h + 1/3);
+    g = hue2rgb(p, q, h);
+    b = hue2rgb(p, q, h - 1/3);
+  }
+
+  return [ r * 255, g * 255, b * 255 ];
+},
+
 
 	pad: function(n)
 	{
@@ -280,6 +307,31 @@ var Helper = {
 			Helper.currentY = null;
 	},
 
+	invertColor: function(hex) {
+    if (hex.indexOf('#') === 0) {
+        hex = hex.slice(1);
+    }
+    // convert 3-digit hex to 6-digits.
+    if (hex.length === 3) {
+        hex = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
+    }
+    if (hex.length !== 6) {
+        throw new Error('Invalid HEX color.');
+    }
+    // invert color components
+    var r = (255 - parseInt(hex.slice(0, 2), 16)).toString(16),
+        g = (255 - parseInt(hex.slice(2, 4), 16)).toString(16),
+        b = (255 - parseInt(hex.slice(4, 6), 16)).toString(16);
+    // pad each with zeros and return
+    return '#' + padZero(r) + padZero(g) + padZero(b);
+},
+
+padZero: function(str, len) {
+    len = len || 2;
+    var zeros = new Array(len).join('0');
+    return (zeros + str).slice(-len);
+}
+
 };
 
 Element.prototype.remove = function() {