Add red/green highlights to debug BT node decorator result

Source/Engine/UI/GUI/Style.cs

@@ -170,6 +170,12 @@ namespace FlaxEngine.GUI
         [EditorOrder(200)]
         public Color ProgressNormal;
 
+        /// <summary>
+        /// The progress error color.
+        /// </summary>
+        [EditorOrder(201)]
+        public Color ProgressError;
+
         /// <summary>
         /// The selection and drag drop highlights colors.
         /// </summary>