Sorry for the bad pictures, but I had to take them using my loupe as a makeshift zoom lens to get any focus at all.
There's some pronounced lines above the T bars and E bars.
Why I think it might just be felt that leaked in from the packaging:
1. It is slightly green (matches felt color) when viewed at different angles.
Why I think it might be some sort of error:
1. No other coins have this, the front of the coin doesn't have this, and the bottom of the coin doesn't have this. If it was falling felt, some should have gotten caught at say the bottom of the U. If it was bad packaging, another coin should have it.
2. At some angles it looks silvery.

This picture was taken at a higher ISO because of shaking, the colors are way off.
