diff --git a/ChangeLog b/ChangeLog
index e7e0f0a75d..9878ba8cca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-07-15  Xavier Claessens  <xclaesse@gmail.com>
+
+	Bug 542523 – GtkTextTag should handle setting properties to NULL
+
+	* gtk/gtktexttag.c (gtk_text_tag_set_property): Unset the color when
+	setting it to NULL instead of displaying a warning.
+
 2008-07-15  Matthias Clasen  <mclasen@redhat.com>
 
 	Bug 479780 – Bookmarks in left pane of FileChooser cannot be renamed
diff --git a/gtk/gtktexttag.c b/gtk/gtktexttag.c
index 34eda38db6..482179b032 100644
--- a/gtk/gtktexttag.c
+++ b/gtk/gtktexttag.c
@@ -1002,7 +1002,9 @@ gtk_text_tag_set_property (GObject      *object,
       {
         GdkColor color;
 
-        if (gdk_color_parse (g_value_get_string (value), &color))
+        if (!g_value_get_string (value))
+          set_bg_color (text_tag, NULL);       /* reset to background_set to FALSE */
+        else if (gdk_color_parse (g_value_get_string (value), &color))
           set_bg_color (text_tag, &color);
         else
           g_warning ("Don't know color `%s'", g_value_get_string (value));
@@ -1015,7 +1017,9 @@ gtk_text_tag_set_property (GObject      *object,
       {
         GdkColor color;
 
-        if (gdk_color_parse (g_value_get_string (value), &color))
+        if (!g_value_get_string (value))
+          set_fg_color (text_tag, NULL);       /* reset to foreground_set to FALSE */
+        else if (gdk_color_parse (g_value_get_string (value), &color))
           set_fg_color (text_tag, &color);
         else
           g_warning ("Don't know color `%s'", g_value_get_string (value));
@@ -1295,7 +1299,9 @@ gtk_text_tag_set_property (GObject      *object,
       {
         GdkColor color;
 
-        if (gdk_color_parse (g_value_get_string (value), &color))
+        if (!g_value_get_string (value))
+          set_pg_bg_color (text_tag, NULL);       /* reset to paragraph_background_set to FALSE */
+        else if (gdk_color_parse (g_value_get_string (value), &color))
           set_pg_bg_color (text_tag, &color);
         else
           g_warning ("Don't know color `%s'", g_value_get_string (value));