add color orange as suggested in issue #504 - Harmonization of road mark colors with OpenDRIVE

Author: MarcelOliver

osi_roadmarking.proto

@@ -121,8 +121,8 @@ message RoadMarking
 
 
         // Boolean flag to indicate that the road marking is taken out of service.
-        // This can be achieved by visibly crossing the road marking with stripes, 
-        // or completly covering a road marking making it not visible. 
+        // This can be achieved by visibly crossing the road marking with stripes,
+        // or completly covering a road marking making it not visible.
         //
         // \image html OSI_RoadMaking_is_out_of_service.jpg width=800px
         //
@@ -206,6 +206,10 @@ message RoadMarking
             // Marking with violet color.
             //
             COLOR_VIOLET = 8;
+
+            // Marking with orange color.
+            //
+            COLOR_ORANGE = 9;
         }
     }
 }