diff --git a/mozilla/themes/classic/global/mac/tree.css b/mozilla/themes/classic/global/mac/tree.css
index 4215618a07e..9e446c9cc7b 100644
--- a/mozilla/themes/classic/global/mac/tree.css
+++ b/mozilla/themes/classic/global/mac/tree.css
@@ -38,6 +38,10 @@ treeitem[selected="true"] > treerow {
 	color: #000000;
 	background-color: Highlight;
 }
+treeitem[dd-dropon="true"] > treerow { 
+	color: #000000;
+	background-color: Highlight;
+}
 
 treecell { 
   white-space: nowrap;
diff --git a/mozilla/themes/classic/global/unix/tree.css b/mozilla/themes/classic/global/unix/tree.css
index 0a6d66f8979..418af9359fa 100644
--- a/mozilla/themes/classic/global/unix/tree.css
+++ b/mozilla/themes/classic/global/unix/tree.css
@@ -25,6 +25,10 @@ treeitem[selected="true"] > treerow {
 	color: highlighttext;
 	background-color: highlight;
 }
+treeitem[dd-dropon="true"] > treerow { 
+	color: highlighttext;
+	background-color: highlight;
+}
 
 treecell 
   { 
diff --git a/mozilla/themes/classic/global/win/tree.css b/mozilla/themes/classic/global/win/tree.css
index 65f5ffcf123..9193b11224e 100644
--- a/mozilla/themes/classic/global/win/tree.css
+++ b/mozilla/themes/classic/global/win/tree.css
@@ -33,6 +33,10 @@ treeitem[selected="true"] > treerow {
 	color: highlighttext;
 	background-color: highlight;
 }
+treeitem[dd-dropon="true"] > treerow { 
+	color: highlighttext;
+	background-color: highlight;
+}
 
 treecell 
   { 
diff --git a/mozilla/themes/modern/global/tree.css b/mozilla/themes/modern/global/tree.css
index c83a1556574..fafef906c5b 100644
--- a/mozilla/themes/modern/global/tree.css
+++ b/mozilla/themes/modern/global/tree.css
@@ -27,6 +27,10 @@ treeitem[selected="true"] > treerow {
 	color: white;
 	background-color: #336699;
 }
+treeitem[dd-dropon="true"] > treerow { 
+	color: white;
+	background-color: #336699;
+}
 
 treecell { 
   white-space: nowrap;