diff --git a/DumpTruck/DumpTruck/FormCarConfig.cs b/DumpTruck/DumpTruck/FormCarConfig.cs
index 7e1ca2a..cc21ecb 100644
--- a/DumpTruck/DumpTruck/FormCarConfig.cs
+++ b/DumpTruck/DumpTruck/FormCarConfig.cs
@@ -73,7 +73,7 @@ DragDropEffects.Move | DragDropEffects.Copy);
             if (_car is DrawningDumpTruck car)
             {
                 labelAddColor.BackColor = (Color)e.Data.GetData(typeof(Color));
-                car.setAddColor((Color)e.Data.GetData(typeof(Color)));
+                ((DrawningDumpTruck)_car).setAddColor((Color)e.Data.GetData(typeof(Color)));
             }
             DrawCar();
         }