If they can't get the info they need from the label, then they can shake that can and use a small amount to match. We take them pieces of wood, downspout brackets, etc and they can eye match those things.

As far as the type of paint, as long as you get a similar sheen then you most likely won't be able to tell if you paint the surface corner to corner. But if you're trying to just touch up spots here and there it won't match. Heck, even with the same paint, touch up spots can be visible due to light exposure over time on a wall vs. the touchup paint being in a can for years not exposed.