Moblo provides a library of ready to use materials (paint / wood / metal / ... ).
Once a shape is selected, click on one of the areas to modify the material.
Use the “replace all” button to apply a single material of your choice to all areas.
When multi-selecting, the materials list shows all the materials applied to your selection. Select a material from the list to replace/modify it. Modifications will apply to all parts in your selection.