Bugaboo, she's super cute! I've never seen a roan that has greyed out before. It would definitely be interesting to see what she would throw if you decided to breed her sometime in the future.
I don't think there's anything wrong with breeding for colour as long as that isn't solely what you're looking for. I'm breeding my solid Pinto mare to a Paint in the spring? Why a Paint you ask? Because I'm hoping for colour - and colour or not, the foal would still be registerable. Lilly is half-Paint but came out solid, so I think a little Pinto foal would be cool, but I've definitely done my homework to make sure, colour or not, I will get a healthy, well-built foal. It's just neat to think of all the colour possibilities you could get!