How to modify the beam sticker material

Step 1: In the Floorplan – Structure – Beam section, select a beam.

Step 2: In the 2D interface, click on the beam and drag it onto the floor plan.

Step 3: Go to Cloud Material – Finishing – Wallpaper – Plain Colour, then drag and drop the material onto the beam

This is also the same process used to apply wall paint colors.