I love to use white, plain or tone on tone.
A good one it you don't want a stark white is Kona Snow.
It's just slightly off white and is great with all fabrics but especially with 30's fabrics.
You can get it at Handcocks of Paducka for $3.98 a yard.
http://www.hancocks-paducah.com/Item--i-KONA-1339 snow
http://www.hancocks-paducah.com/Item--i-KONA-1387 white