Can't color a XML Unstructured Grid (*.vtu)

[graysuit (Gray Programmerz)]

@Kenichiro-Yoshimi

I am not sure if this is a proper solution, but it might work if you create a new mapper at the end of the setColors function.

            output.GetPointData().SetScalars(colors);

+           vtkDataSetMapper mapper = vtkDataSetMapper.New();
+           mapper.SetInput(output);
+           actor.SetMapper(mapper);
        }

I got that solution from here:
https://discourse.paraview.org/t/how-to-color-unstructured-grid-vtu/10140/2