diff --git a/MatterControlLib/PartPreviewWindow/SelectedObjectPanel.cs b/MatterControlLib/PartPreviewWindow/SelectedObjectPanel.cs
index f0643c9c1..ca0025b04 100644
--- a/MatterControlLib/PartPreviewWindow/SelectedObjectPanel.cs
+++ b/MatterControlLib/PartPreviewWindow/SelectedObjectPanel.cs
@@ -302,7 +302,14 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 				{
 					if (selectedItem.Color != colorField.Color)
 					{
-						undoBuffer.AddAndDo(new ChangeColor(selectedItem, colorField.Color));
+						if (colorField.Color == Color.Transparent)
+						{
+							undoBuffer.AddAndDo(new ChangeColor(selectedItem, colorField.Color, PrintOutputTypes.Default));
+						}
+                        else
+                        {
+							undoBuffer.AddAndDo(new ChangeColor(selectedItem, colorField.Color, PrintOutputTypes.Solid));
+						}
 					}
 				};
 
@@ -384,7 +391,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					var currentOutputType = selectedItem.OutputType;
 					if (currentOutputType != PrintOutputTypes.Solid && currentOutputType != PrintOutputTypes.Default)
 					{
-						undoBuffer.AddAndDo(new ChangeColor(selectedItem, colorField.Color));
+						undoBuffer.AddAndDo(new ChangeColor(selectedItem, colorField.Color, PrintOutputTypes.Solid));
 					}
 
 					SetButtonStates();
diff --git a/MatterControlLib/PartPreviewWindow/View3D/UndoCommands/ChangeColor.cs b/MatterControlLib/PartPreviewWindow/View3D/UndoCommands/ChangeColor.cs
index 09547b1f2..dac3ca58c 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/UndoCommands/ChangeColor.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/UndoCommands/ChangeColor.cs
@@ -41,10 +41,12 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 		private List<Color> itemsColor = new List<Color>();
 		private List<IObject3D> itemsToChange = new List<IObject3D>();
 		private Color color;
+		private PrintOutputTypes outputTypeToSet;
 
-		public ChangeColor(IObject3D selectedItem, Color color)
+		public ChangeColor(IObject3D selectedItem, Color color, PrintOutputTypes outputType)
 		{
 			this.color = color;
+			this.outputTypeToSet = outputType;
 			if (selectedItem is SelectionGroupObject3D)
 			{
 				SetData(selectedItem.Children.ToList());
@@ -69,7 +71,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 		{
 			foreach(var item in this.itemsToChange)
 			{
-				item.OutputType = PrintOutputTypes.Solid;
+				item.OutputType = outputTypeToSet;
 				item.Color = color;
 			}
 		}
diff --git a/MatterControlLib/SlicerConfiguration/EngineMappingsMatterSlice.cs b/MatterControlLib/SlicerConfiguration/EngineMappingsMatterSlice.cs
index 0e6c10543..599f5835a 100644
--- a/MatterControlLib/SlicerConfiguration/EngineMappingsMatterSlice.cs
+++ b/MatterControlLib/SlicerConfiguration/EngineMappingsMatterSlice.cs
@@ -324,7 +324,7 @@ namespace MatterHackers.MatterControl.SlicerConfiguration
 				if (supportObjects.Any())
 				{
 					// add a flag to the merge rules to let us know there was support
-					mergeRules += "S" + AddObjectsForExtruder(supportObjects, holes, outputOptions, ref savedStlCount);
+					mergeRules += "S" + AddObjectsForExtruder(supportObjects, null, outputOptions, ref savedStlCount);
 				}
 
 				var wipeTowerObjects = meshItemsOnBuildPlate.Where((item) => item.WorldOutputType() == PrintOutputTypes.WipeTower);
@@ -639,7 +639,7 @@ namespace MatterHackers.MatterControl.SlicerConfiguration
                     }
 				}
 
-				if (holes.Any())
+				if (holes?.Any() == true)
 				{
 					bool firstHole = true;