all themes now have contrasting text colors based on slide bg

css/theme/source/moon.scss

@@ -50,7 +50,8 @@ $linkColor: $blue;
 $linkColorHover: lighten( $linkColor, 20% );
 $selectionBackgroundColor: $magenta;
 
-
+// Change text colors against light slide backgrounds
+@include light-bg-text-color(#222);
 
 // Theme template ------------------------------
 @import "../template/theme";