Try hydrogen perxiode. I moved into our home a few years ago our carpet was off white. My youngest child Peter broke an ink pen on the carpet and left it there to bleed all over. I had a huge spot on the carpet of black ink. I searched the internet and found that I could use hydrogen perxiode on the carpet. It didn't fade it at all but I have a hunch its because its a syncthetic fiber. It might work on your fabric too. Worth a try.