Make the Similar colors detector more relax

lib/tools/colorDiff.js

@@ -5,7 +5,7 @@ var parse   = require('parse-color');
 
 var colorDiff = function() {
 
-    var COLOR_DIFF_THRESHOLD = 0.9;
+    var COLOR_DIFF_THRESHOLD = 0.7;
 
     this.compareAllColors = function(data) {
         debug('Starting to compare all colors...');