I didn't find that the black fabric I bought bled, but it did smell when it was wet. At first I though I had done some damage to my wash machine, burnt up a belt or something. It was the fabric. I have no idea what they dyed it with, but the intense black color came with that funky smell that did not completely wash out after three tries with varying detergents. It does not smell when dry though.
I prewash almost all of my fabric, I do toss in a white cotton rag to see if the color bleeds since I can't lift the lid on my HE washer once it gets started like I could on my old machine. I usually add a cup of vinegar to the rinse water to set any questionable colors. I have heard salt will do the same, but I'm not sure I want salt in my machine. I may cut the amount back to 1/2 cup now since the machine uses half the water.
I haven't used the color catchers, but everybody seems to swear by them.