The first step is to choose a user parameter by clicking "Indicate Parameter". This parameter will be used to copy the reference level of  MEP linear elements (such as pipes, ducts, conduits, and cable trays) because the reference level of these elements cannot be used in view filters. 

Once you've indicated the parameter, click the "Apply Filters" button. The script will apply one color to all MEP elements belonging to the same level. The plugin uses random colors; if you don't like the chosen colors, apply the filters again until you're satisfied.

The plugin also includes a "Delete Filters" button. This button deletes created filters from the model and cleans the user parameter of the copied values.

Important information:

The plugin copies the reference level value into the user parameter. Once the model has been changed, the data in the user parameter will not be accurate. After finishing the visual inspection, deleting the view filters and values copied into the user parameter is highly recommended.

Comments:

The plugin processes the most common MEP categories. Please comment if you would like me to add more categories.