Big Girls Vintage 16 1/2 Aqua Blue Nylon One Piece Pantsuit

There are a series of stains along the upper leg. Part of them are covered by the top fluff overhang, and the others may be visible. I hand washed this in oxiclean to try and get them out and it definitely faded them. I’m thinking it is from some kind of paint or ink, as I was messy and liked art supplies.