I like your idea of reducing the border, but what you do depends on your skills and how much effort you want to put into it. As has been said, you have a blank canvas and the possibilities are endless. If you want to keep it Amish, stay with solids. If you don't care about that, choose nearly any fabrics you like. Treat what you have the same as if it were white, except that if you add really light colors might need an interfacing to keep the background from showing through. Have fun with it.