I found a description on backyardgardener, it says it's an intense scarlet ..
http://www.backyardgardener.co...
There's a 'Professor Sargent' on this site which is probably the same but it's an intense scarelt too..
http://www.jimscamellias.co.uk...
If yours opens up with white bits in the middle I wouldn't mind betting it's one of Nuccio's.
Actually it looks a good match on this site, maybe the rest are not correct!
http://www.lovcam.org/nomenc.p...