Two summers ago, I bought 6 skeins of Berocco Comfort Chunky in a lovely scarlet red, and 4 skeins of the same in white.
I was going to make a cardigan out of it.
During the construction process, I noticed that the red tended to get everywhere... on the white yarn, on white shirts, and all that. I shrugged it off and kept going, finishing the cardigan and wearing it a bit.
Fast forward to earlier this year, and I realized I wasn't wearing the cardigan, so I decided to rip it up and make a different one using a different stitch and a different pattern. But the colour bleed still concerned me, so I asked around, going so far as to email Berocco to ask what to do about the bleeding.
They suggested vinegar, but also said that the bleeding was likely only to get worse after I washed it. And they then replaced my yarn with Vintage Chunky.
Through the entire process, which took a week at most, they were nice and pleasant about it, as was I. I like the yarn, and still like the sweater, BUT... the bleeding is going to likely annoy me.
However, directly dealing with the yarn company has definitely made me feel better about using their product, at least.