I will agree with NDAppy. I am still partially unclear on the line between brownskin and buckskin, but I think the deciding factor is that she's colored like a brown horse (with the lighter patches behind her elbows, on her flanks, and on her thighs), plus, she's just darker than your typical sooty buckskin. She is certainly stunning, either way.
As for the stud, no doubt at all about the bay roan. Some roan horses get those very defined stripes on their ribcage. I'm not sure what causes it.