Answer:
In RFEM and RSTAB, you can save user-defined colors for materials. This way, you can change the color display of the solid model.
To change the color of a material, open the Edit Material dialog box. Then, click the "Edit Color and Texture of Material" button that opens the "Edit Material Color and Texture" dialog box. If you assign a different color to the material, all structural components with this material will be displayed in this color in the rendering mode.