Stain on pink linen blouse

I have a 100% linen blouse, in a light pink color. It somehow acquired a dark stain on the front. I have no idea what caused the stain; I assume it’s something I was eating but I’m not certain. I treated the stain with Zout spray, let the blouse sit for a few minutes, then washed it in cold water and air-dried the blouse. The stain is still there <sobbing> Please help!

u/KismaiAesthetics, laundry wizard, if you’re out there, I need a rescue!