It sorta works but tends to throw the stir bar, because they have a curved bottom. At least in my experience. I have made starters in them before, but I check them somewhat regularly to make sure they are still swirling OK.
I don't think the brown glass makes any difference in a starter, and I KNOW you don't want a cap on there when you're making one. Frankly I think clear glass is better because it makes it easier to see the yeast when you decant/pitch later.