Speaking of yellow, couple of years ago I was taking a wallhanging class, the quilting was done before hand, it was a diagonal grid, so we used yellow chalk, that left a wonderful line to follow, until it came to washing it, quilted with a metallic thread and the yellow remained, yes you have to be careful with yellow, unless it is light and you are going over it with yellow. That was a huge disappointment, yes I am careful with it. Red, too. I think the first thing I would check is when it is wet if it bleeds all over, that can be a problem.