diff --git a/lib/context2d.js b/lib/context2d.js
index 8acf9dc..f637416 100644
--- a/lib/context2d.js
+++ b/lib/context2d.js
@@ -202,15 +202,38 @@ var parseColor = exports.parseColor = function(str){
   }  
 };
 
-// adapted from ABC code at http://www.w3.org/TR/css3-color/#hsl-color
+/**
+ * HSLA -> RGB.
+ *
+ * @param {Number} h
+ * @param {Number} s
+ * @param {Number} l
+ * @param {Number} a
+ * @return {Array}
+ * @api private
+ */
+
 function hsl2rgb(h,s,l,a) {
   var m2 = l <= 0.5 ? l*(s+1) : l+s-l*s
     , m1 = l*2-m2;
-  return [ Math.round(hue2rgb(m1, m2, h+1/3) * 255),
-           Math.round(hue2rgb(m1, m2, h) * 255),
-           Math.round(hue2rgb(m1, m2, h-1/3) * 255),
-           a ]
+  return [
+      Math.round(hue2rgb(m1, m2, h+1/3) * 255)
+    , Math.round(hue2rgb(m1, m2, h) * 255)
+    , Math.round(hue2rgb(m1, m2, h-1/3) * 255)
+    , a
+    ];
 }
+
+/**
+ * Hue to RGB
+ *
+ * @param {Number} m1
+ * @param {Number} m2
+ * @param {Number} h
+ * @return {Number}
+ * @api private
+ */
+
 function hue2rgb(m1,m2,h) {
   if (h<0) h = h+1;
   if (h>1) h = h-1;