M.D.
Rit (that makes Rit dyes) makes a product called Color Run Remover. I have had luck with this in the past. Doesn't work as well on multi colored clothes but since your sweater is cream it should be okay. You normally put the whole package into your washing machine. But if it's just a small stain, I think you could make a small solution of it and just treat the stain. I think Walmart should carry it. It might be in the laundry section or it could be in craft section because it will be with the Rit dye display. Good luck!