I'm not careful about the grape variety, as long as the color of the bottle look like my photos! I use two main colors, light green for the Sangria collection and a darker green for the other collection, which I should call something other than Dark Green!
Red wine bottles look a lot alike once stripped of their labels and cut into small pieces! What is most important is never to mix glass from two different bottles together! It forces me to organize myself, which is really not in my nature!