Color-catchers are some of my favorite laundry products. The Carbona brand were the first I used. They come out of the washing machine with very obvious markings, which helped me feel confident about their effectiveness.
The Dye Grabber is true to its name--it grabs any color that bleeds and saves whatever else is in the load. To my surprise and delight, the Dye Grabber even removed dye stains from a few favorite pieces of clothing that I thought had been permanently ruined when they accidentally got washed with a new pair of jeans. Now that I've found this product, I'll never do laundry without it again!