Baby puke

FarmWife 🌾 • 2015 👧🏼 2017 👼🏼👼🏼 2018 👧🏼 🌈 2020 👶🏼
What is this? We were at the doctor for her four month check up on Tuesday, I mentioned she was a little congested and the doctor said just sounded like a little upper respiratory infection. Told me to just give her Tylenol. She just threw this up and it's almost like mucus with a little bit of chunky milk, but what is the brown in it?