Selection color is not shown when entities have assigned colors
For now, if we load a model in, we can see the selection color when no entity color has been assigned. After assigning colors to entities, we can no longer see the selection color.
It's because PV's logic is that which comes last would be shown on the top in 2D mode. In the first case, selection color is the last joiner. Then after assign color operation, entity color is the last joiner. In 3D mode, you would see Z fighting.
Solution: Since we have two geometryRepresentations as one for the model and another one for the selection, we would turn the block visibility of the selected entities' to be off then only show their selection representation. In this way, we avoid the above problem.