Index: /trunk/src/org/openstreetmap/josm/data/Preferences.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/Preferences.java	(revision 12941)
+++ /trunk/src/org/openstreetmap/josm/data/Preferences.java	(revision 12942)
@@ -986,5 +986,6 @@
             return tr("Layer: {0}", tr(I18n.escape(m.group(1))));
         }
-        return tr(I18n.escape(colornames.containsKey(o) ? colornames.get(o) : o));
+        String fullKey = COLOR_PREFIX + o;
+        return tr(I18n.escape(colornames.containsKey(fullKey) ? colornames.get(fullKey) : fullKey));
     }
 
Index: /trunk/src/org/openstreetmap/josm/gui/preferences/display/ColorPreference.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/preferences/display/ColorPreference.java	(revision 12941)
+++ /trunk/src/org/openstreetmap/josm/gui/preferences/display/ColorPreference.java	(revision 12942)
@@ -145,5 +145,5 @@
 
     private static String getName(String o) {
-        return Main.pref.getColorName("color." + o);
+        return Main.pref.getColorName(o);
     }
 
Index: /trunk/test/unit/org/openstreetmap/josm/data/PreferencesTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/data/PreferencesTest.java	(revision 12941)
+++ /trunk/test/unit/org/openstreetmap/josm/data/PreferencesTest.java	(revision 12942)
@@ -32,6 +32,6 @@
     @Test
     public void testColorName() {
-        assertEquals("color.layer {5DE308C0-916F-4B5A-B3DB-D45E17F30172}.gpx",
-                Main.pref.getColorName("color.layer {5DE308C0-916F-4B5A-B3DB-D45E17F30172}.gpx"));
+        assertEquals("Layer: {5DE308C0-916F-4B5A-B3DB-D45E17F30172}.gpx",
+                Main.pref.getColorName("layer {5DE308C0-916F-4B5A-B3DB-D45E17F30172}.gpx"));
     }