Black staining on rubber lid gasket??

Hi all!

I got some kind of black staining on my owala from lipstick/lip gloss. Not too sure what because I noticed it on the spout and cleaned it after! I've tried scrubbing this out, but it's not coming off :( not sure if it's permanently stained, but hoping for some advice or insight on what this is/ what to do!

Owala is currently out of stock for their gasket, so I know that I will need to wait until they come back for a replacement :')