document needed color format

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@56997 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/r.in.wms/r.in.wms.py

@@ -140,7 +140,8 @@ This program is free software under the GNU General Public License
 #%option
 #% key: bgcolor
 #% type: string
-#% description: Background color
+#% label: Background color
+#% description: Format: 0xRRGGBB
 #% guisection: Map style
 #%end