This is a cafe in the bottom of a hostel, and while it seems to have a decent atmosphere for a hostel, the coffee is nothing to write home about. It's made with those little tea bag inserts, guaranteeing stale coffee and inexperienced baristas. While is wasn't burnt (which is unusual in Rome) it was thin and unimpressive.
Reviews of The Yellow
A backpacker hostel that I was staying at and was quite surprised to find the coffee was awesome, but only every couple of cups. Turns out there's an Australian girl who works the machine like a goddess! Don't bother unless she makes it for you. As for atmosphere it's a bar normally so don't expect too much of a cafe atmosphere.