Correct Decrease Colour

Author: Roeterdink

Source/RunActivity/Viewer3D/RollingStock/MSTSLocomotiveViewer.cs

@@ -2999,6 +2999,7 @@ public override void PrepareFrame(RenderFrame frame, ElapsedTime elapsedTime)
             //          <CSComment> Now speedometer is handled like the other digitals
 
             base.PrepareFrame(frame, elapsedTime);
+            digital.OldValue = Num;
         }
 
         public override void Draw(GraphicsDevice graphicsDevice)
@@ -3072,6 +3073,8 @@ public string GetDigits(out Color DrawColor)
                     displayedText = String.Format(Format, Num);
                     DrawColor = Color.White;
                 }
+                digital.OldValue = Num;
+
                 // <CSComment> Speedometer is now managed like the other digitals
 
                 return displayedText;
@@ -3148,6 +3151,8 @@ public string GetDigits(out Color DrawColor)
                 {
                     displayedText = String.Format(Format, Num);
                 }
+                digital.OldValue = Num;
+
                 // <CSComment> Speedometer is now managed like the other digitals
 
                 return displayedText;