diff --git a/prototype/UI/index.html b/prototype/UI/index.html
index 54feae8a7..fce2a1841 100644
--- a/prototype/UI/index.html
+++ b/prototype/UI/index.html
@@ -4,11 +4,11 @@
   	<title>semantic-diff</title>
     <style type="text/css">
     .insert {
-        outline: 1px solid green;
+        outline: 1px solid #c1e9c1;
         margin-left: 50%;
     }
     .delete {
-        outline: 1px solid red;
+        outline: 1px solid #f1c0c0;
         margin-right: 50%;
     }
     .replace {