diff --git a/README.md b/README.md
index 7037a41..00916a3 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,6 @@
   
 Basic HTML page that helps pick a spine color based on a drag-and-droppable cover image.
   
+Uses [lokesh/color-thief](https://github.com/lokesh/color-thief).
+  
 </div>