I think that the baby shampoo, detergent, soap, or re-formulated Woolite fades the dyes - not the white vinegar.
Woolite was originally much closer to baby shampoo for protein fibers (wool & silk) but with so many people using it for all "fine washables", including artificial fibers, the original formula changed over time.
Because they couldn't come up with a second bottle labelled "Woolite 2 - for artificial fibers" instead, I suppose.
They had a silk rug that a cat horked up a hair ball on. Her husband blanched when told how much it would cost to dry clean it and told her to just use cold water on it. She told him that would fade the dyes and ruin the value of the rug. He told her that she must be mistaken.
They now have a faded silk rug that reminds him not to question her....and the cat can now safely hork up hairballs on. Except, being a cat, he uses a different floor covering for new hairballs.....