diff --git a/lib/extendStringPrototype.js b/lib/extendStringPrototype.js
index bbb9bcc..67374a1 100644
--- a/lib/extendStringPrototype.js
+++ b/lib/extendStringPrototype.js
@@ -86,7 +86,7 @@ module['exports'] = function () {
           addProperty(prop, function () {
             var ret = this;
             for (var t = 0; t < theme[prop].length; t++) {
-              ret = exports[theme[prop][t]](ret);
+              ret = colors[theme[prop][t]](ret);
             }
             return ret;
           });