Fix jupyter display missing opacity (#1941)

Author: lorenzncode

cadquery/occ_impl/jupyter_tools.py

@@ -168,7 +168,7 @@ def display(shape):
         payload.append(
             dict(
                 shape=toString(shape),
-                color=DEFAULT_COLOR,
+                color=DEFAULT_COLOR + (1,),
                 position=[0, 0, 0],
                 orientation=[0, 0, 0],
             )