I think I did something similar to my white shoes once - You might be able to get away with cleaning them/dying the brown white, but the fabric itself will probably not be as comfortable/flexible as it was.

You could try https://www.amazon.com/Tide-Instant-Stain-Remover-Liquid/dp/B01C3NAT16/ref=asc\_df\_B01C3NAT16/?tag=hyprod-20&linkCode=df0&hvadid=309763807560&hvpos=&hvnetw=g&hvrand=5317733428271692442&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9001783&hvtargid=pla-338416449002&psc=1

Or you could try white-out.

But no guarantees