fix: handle properly multi_colors=False (#172)

Co-authored-by: pyansys-ci-bot <[email protected]>

Author: RobPasMue

doc/changelog.d/172.fixed.md

@@ -0,0 +1 @@
+fix: handle properly multi_colors=False

src/ansys/tools/visualization_interface/backends/pyvista/pyvista_interface.py

@@ -356,7 +356,7 @@ def set_add_mesh_defaults(self, plotting_options: Optional[Dict]) -> None:
         # This method should only be applied in 3D objects (bodies and components)
         if "smooth_shading" not in plotting_options:
             plotting_options.setdefault("smooth_shading", True)
-        if all(entry not in plotting_options for entry in ["color", "multi_colors"]):
+        if "color" not in plotting_options and not plotting_options.get("multi_colors", False):
             plotting_options.setdefault("color", Color.DEFAULT.value)
 
     @property