This blog will follow the construction of a double deck N-scale model railroad. This model railroad will be based on the BNSF railroad.
I have used a black fascia on 3 of my layouts, so I guess my bias is towards black. I use a satin latex so that it's not glossy, but also not flat. Seems to work for me.
Go with a neutral color that does not clash/contrast with the walls and flooring in your layout room. The objective is for your eyes to be drawn to the layout, with the fascia framing the scene without drawing attention to the fascia itself. Darker shades of grey can work well. Olive green can work well. Avoid colors that are found within your scene like tans or pale colors.