diff --git a/dialog-polyfill.css b/dialog-polyfill.css
index 6b38bf0..2c9063d 100644
--- a/dialog-polyfill.css
+++ b/dialog-polyfill.css
@@ -11,7 +11,9 @@ dialog {
   border: solid;
   padding: 1em;
   background: white;
+  background-color: Canvas;
   color: black;
+  color: CanvasText;  
   display: block;
 }
 
@@ -34,4 +36,4 @@ dialog.fixed {
   position: fixed;
   top: 50%;
   transform: translate(0, -50%);
-}
\ No newline at end of file
+}