My wife's 335is Coupe is Le Mans Blue, an exclusive color for that model. I don't see that as making it any less exclusive for the E9x M3.
Interlagos Blue was offered both on the Z4 M and the E46 M3.
It's a few years away, but I'm planning on Estoril Blue II for my M4.
Mine: 2006 Z4 Roadster | Interlagos Blue Metallic | Black Extended Nappa Leather | Carbon Leather Trim | Premium | Navigation | Heated Seats | iPod Adapter | Purchased 7/19/12
Hers: 2011 335is Coupe | Le Mans Blue Metallic | Black Dakota Leather | Dark Glacier Aluminum | 6MT | Premium | Convenience | Heated Seats | Navigation | Harmon Kardon | iPod/USB | European Delivery 5/12/11