To Open a Material Palette(s)

Select the Apply Material tool.
In the tool settings window, click the Open Palette icon.

The Open Palette dialog opens.
In the Open Palette dialog, select a material palette file.
Click the OK button.
The dialog closes. The name of the material palette file appears in the Material option menu of the settings window and a sample of it displays in the Material Preview Window.
(Optional) Repeat steps 2 to 4 to load additional palette files.
Note: If you click the Browse for DGN and PAL file icon in the Open Palette dialog, an Open dialog displays. In addition to external PAL files, a design file (DGN) can be opened if local materials are used.