Bell Magic Lay-ups

Is there a good way to tell the difference between white gold and black gold lay-ups when looking at used Bell Magics when they have colored gelcoat?

Recycling,
http://www.paddling.net/message/showThread.html?fid=advice&tid=1228255

Thanks…but still not sure.
OK, so both white and black gold have the “tweed” kevlar as the inner fabric. With the colored gel, you can’t see the outer layer so is the difference between the WG core mat center and the BG foam core something you can tell just by looking at it? I’ve owned several foam core canoes but am not sure I know what “core mat” is.