How do i use brick Generator like a mask to use Wood panels?

https://youtu.be/3kbOSpcaQU4?t=61

So here, i want can get the brick layout in the shape of the wood panels. But for the "Panel" part, i want to select any wood material or any material i want. Also I want to use a specific color for the "Mortar" between the panels.

But whenever i use a new layer, it just colors everything the same. I cant make the mortar color any different.