diff --git a/cura/Scene/ConvexHullNode.py b/cura/Scene/ConvexHullNode.py
index 4c79c7d5dc..886ed93ad3 100644
--- a/cura/Scene/ConvexHullNode.py
+++ b/cura/Scene/ConvexHullNode.py
@@ -1,7 +1,10 @@
 # Copyright (c) 2015 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
+from typing import Optional
 
 from UM.Application import Application
+from UM.Math.Polygon import Polygon
+from UM.Qt.QtApplication import QtApplication
 from UM.Scene.SceneNode import SceneNode
 from UM.Resources import Resources
 from UM.Math.Color import Color
@@ -16,7 +19,7 @@ class ConvexHullNode(SceneNode):
     #   location an object uses on the buildplate. This area (or area's in case of one at a time printing) is
     #   then displayed as a transparent shadow. If the adhesion type is set to raft, the area is extruded
     #   to represent the raft as well.
-    def __init__(self, node, hull, thickness, parent = None):
+    def __init__(self, node: SceneNode, hull: Optional[Polygon], thickness: float, parent: Optional[SceneNode] = None) -> None:
         super().__init__(parent)
 
         self.setCalculateBoundingBox(False)
@@ -25,7 +28,11 @@ class ConvexHullNode(SceneNode):
 
         # Color of the drawn convex hull
         if not Application.getInstance().getIsHeadLess():
-            self._color = Color(*Application.getInstance().getTheme().getColor("convex_hull").getRgb())
+            theme = QtApplication.getInstance().getTheme()
+            if theme:
+                self._color = Color(*theme.getColor("convex_hull").getRgb())
+            else:
+                self._color = Color(0, 0, 0)
         else:
             self._color = Color(0, 0, 0)
 
@@ -75,7 +82,7 @@ class ConvexHullNode(SceneNode):
 
         return True
 
-    def _onNodeDecoratorsChanged(self, node):
+    def _onNodeDecoratorsChanged(self, node: SceneNode) -> None:
         convex_hull_head = self._node.callDecoration("getConvexHullHead")
         if convex_hull_head:
             convex_hull_head_builder = MeshBuilder()