Can you paint granule surface modified to match shingles
Use hydro-stop finish coat. You can get it to almost any color and it is a UV protectant. www.hydro-stop.com
I don't see why not. You will have to watch out for the expansion/contraction rates of the modified against the paint though, it will almost certainly be different and subsequently crack. You know you can get modified in different colors right? Soprema even does red and blue.