Unless you're doing it specifically for a reason, like if you have two teams that are stylistically green and red and you want their trash cans to match.
Otherwise they wire mesh is painted black, or a very dark green. Also, there is a usually a plastic trash can inside the wire mesh, or at least a clear/black trash bag.
EDIT: Why no image tags in the editing section? Seems like it would make sense to have them on for here.