Young Great Tit.
Now if there were a pair of them.... 
Green? 
Sorry, those are the only ones that regularly frequent our garden, and that I would be allowed to post on the net!
Actually I happen to have a "Great Tit" pin from the RSPB that I wear on my Fleece.
We were in a Pub, and the wife asked what I prefered, answer "Great tits", and she bought me it.
I still dont think she has caught on (Its the last vestiges of resistance after 32 years of marriage).
Cheers