On light backgrounds, I like to use Frixion pens, or Crayola Ultra Washable markers. I always wash my quilts after they're finished, and I've had good luck with these washing out. If you don't want to wash, maybe the silver Roxanne pencils? The purple pens that disappear in the air (or when you spritz them with water, if you live in a very dry climate) are good, too, as long as you plan on doing your quilting right away.
It's hard to find things that brush off light fabrics. Coloured chalk does tend to stain, so I avoid it whenever possible. I've actually had better luck washing out ballpoint pen than coloured chalk.