use SolidColor instead of vtkBlocksColor as default array color for monoblock multiblock datasets
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
Since ParaView 5.0, the default array color for multiblocks dataset is vtkBlocksColor, while it make sense for actual multiblocks dataset, it's only perturbing for multiblock dataset containing only one block, with a display of a useless big legend.
Using SolidColor in this case would resolve this problem.