Purple stains on white sheets

I'm staying at a hotel and typically sleep in a bonnet. My bonnet is purple. I sweated so much while I was sleeping that apparently my bonnet bled on the white sheets and pillow cases. I've never seen this before because I don't own anything that's white. I've had my bonnet for a year now and it's been washed a few times. Never thought it would do this! How do I get the stains out? The hotel bleaches everything but they're going to charge me anyway, $100 an item. Help!