diff --git a/src/openseadragon.js b/src/openseadragon.js
index e9add543..de88f717 100644
--- a/src/openseadragon.js
+++ b/src/openseadragon.js
@@ -159,7 +159,9 @@
   * @property {Boolean} [debugMode=false]
   *     TODO: provide an in-screen panel providing event detail feedback.
   *
-  * @property {String} [debugGridColor=['#437AB2']]
+  * @property {String} [debugGridColor=['#437AB2', '#1B9E77', '#D95F02', '#7570B3', '#E7298A', '#66A61E', '#E6AB02', '#A6761D', '#666666']]
+  *     The colors of grids in debug mode. Each tiled image's grid uses a consecutive color.
+  *     If there are more tiled images than provided colors, the color vector is recycled.
   *
   * @property {Number} [blendTime=0]
   *     Specifies the duration of animation as higher or lower level tiles are
@@ -1207,7 +1209,7 @@ function OpenSeadragon( options ){
 
             //DEVELOPER SETTINGS
             debugMode:              false,
-            debugGridColor:         ['#437AB2']
+            debugGridColor:         ['#437AB2', '#1B9E77', '#D95F02', '#7570B3', '#E7298A', '#66A61E', '#E6AB02', '#A6761D', '#666666']
         },