By default Piping Insulation Layer color is same for all piping sizes
To change the insulation color in piping, so it has the same color as the pipe, you must edit the COMPPROP.EBS file.
For existing pipes in a model and existing models you need to redraw the model with menu Piping>Piping Tools>Representations.
If above problem still persist, then please create a Service Request and contact the Bentley Product Advantage group. Please include a list of all relevant details to get in depth analysis for a solution or workaround.
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