After choosing to go with a charcoal brush style for the UI elements, I had to figure out how to make the style a bit more alive as the UI would look too flat without any material effects. I wanted to create an almost ethereal-like effect, so I used a tiled smoke texture as the 'effect texture' to apply the desired effect on the selector (highlight).

I used the same material graph for the loading screen elements so as to keep the style consistent.