I've made a couple. The one I have now is from a fellow quilter who was moving. She used grey flannel and attached it to poster board. I stapled it to my wall, and I've had many quilts on it. I often use pins to secure strips etc to the flannel. I've also used the blue foam sheets you get at the lumber yard (for insulating a house) and sprayed adhesive to it.
For IQF classes they ask for black felt pieces maybe 18 inches square to look at choices for your blocks.
The grey is better than the white (my first one)because it is more neutral. You tend not to see it when you look at your quilt. I think you could use a tan as well.