The only time I used coffee to stain anything (on purpose!) was when I made a coffee filter wreath for my mom. She's a smoker, so anything white in her house doesn't stay white for long, but she also LOVES coffee. So I dyed the filters with some super strong coffee so they were a nice tan colour and it had the added bonus of smelling like coffee lol She loves it and tells me it still smells like coffee (and I made it over a year ago!). Can't say I ever thought about dying clothes with it though, smart idea!