diff --git a/src/evolution-webcal-notify.c b/src/evolution-webcal-notify.c
index 77251d4..f05f991 100644
--- a/src/evolution-webcal-notify.c
+++ b/src/evolution-webcal-notify.c
@@ -252,7 +252,6 @@ void e_webcal_query_user (const gchar * name, const gchar * desc,
   GdkColor color;
   GSList * l;
   gchar * scolor;
-  guint32 icolor = 0;
 
   tmpuri = soup_uri_new (caluri);
   tmpname = g_path_get_basename (tmpuri->path);
@@ -548,8 +547,9 @@ void e_webcal_query_user (const gchar * name, const gchar * desc,
     g_free (ref_str);
 
     gtk_color_button_get_color (GTK_COLOR_BUTTON (cbutton), &color);
-    icolor = ((color.red >> 8) << 16) | ((color.green >> 8) << 8) | (color.blue >> 8);
-    e_source_set_color (source, icolor);
+    scolor = gdk_color_to_string (&color);
+    e_source_set_color_spec (source, scolor);
+    g_free (scolor);
 
     if (!strncmp (caluri, WEBCAL_BASE_URI, 9)) {
       e_source_set_relative_uri (source, caluri + 9);
