Prevent unreable text with light-on-dark system colors by using hardcoded black foreground color when on top of a background image that is light. b=103498 r=jag sr=hewitt

themes/classic/communicator/mac/dialogOverlay.css

@@ -13,6 +13,7 @@
     padding               : 0px 0px 3px 0px;
     min-height            : 0px;
     background-image      : url(chrome://communicator/skin/smallheader-bg.gif);
+    color                 : black;
   }
 
 .box-smallheader-left 
@@ -42,6 +43,7 @@
     border-bottom         : 1px solid #FFFFFF;
     background-color      : #FFFFFF;
     background-image      : url(chrome://communicator/skin/smallheader-bg.gif);
+    color                 : black;
   }
 
 .box-header-header 

themes/classic/communicator/sidebar/mac/sidebar.css

@@ -31,6 +31,7 @@
     background-color      : #DDDDDD;
     padding               : 3px 5px 3px 6px;
     background-image      : url("chrome://communicator/skin/smallheader-bg.gif");
+    color                 : black;
   }
 
 .sidebar-header-text  

themes/classic/communicator/win/dialogOverlay.css

@@ -16,6 +16,7 @@
     padding               : 0px 0px 3px 0px;
     min-height            : 0px;
     background-image      : url(chrome://communicator/skin/smallheader-bg.gif);
+    color                 : black;
   }
 
 .box-smallheader-left