What a shame. Velveteen is a cotton fabric, subject to both shrinking and bleeding. Pre-washing would have been a good idea, but that's not very helpful now. The color that came off on your shirt will probably come out in the wash, but that probably isn't what you're worried about. What is the rest of your crazy quilt made of? Would the whole thing be washable, with a bunch of color catchers or synthrapol? Is it to be a wall hanging, in which case it doesn't matter if the color bleeds?