Bleaching off-white yarn?

When I was working on this blanket, all the yarn I was using looked white, due to the lighting conditions I was working in. But now that I’ve brought the blanket out into different lighting, I can see some yarn was actually this off-white yellowish yarn. Hopefully the stripe is visible enough in the picture. Anything I can do? I’m pretty sure it’s cotton. blanket

I can see the yellowish area. Was it a different ball of yarn, it looks all attached?

Oh no! Is the large white section at the end of your work or the beginning? If you can unravel it and wash it, the stain may go, and then you can use the same yarn to reknit it. Or do you have any more white?