diff --git a/trac/htdocs/libcaca.css b/trac/htdocs/libcaca.css
index f49c399..625bd2e 100644
--- a/trac/htdocs/libcaca.css
+++ b/trac/htdocs/libcaca.css
@@ -751,7 +751,7 @@ div.sidebar {
     -moz-border-radius: 5px;
     -webkit-border-radius-bottomright: 5px;
     border-radius-topleft: 5px;
-    background: #D7E6FF;
+    background: rgba(215,230,255, 0.8);
     border: 1px solid #2C1F1C;
     float: right;
     overflow: hidden;