I use white towels. Towels because she can fling them around and easily rearrange them, plus they are easily washed. White so that I can see if there is any discharge and immediately see what color. Sheets also work.
Good Luck.
I also use light colored towels for the same reasons Susan stated.
I prefer to do laundry than to mess with newspapers.
I use towels all the way through delivery, changing as we progress.