A very fluffy bird! I think the chances of an olive egger are maybe 1 in 4. Not knowing a single thing about egg shell genetics that is. It would all depend on the strength of the blue egg gene in the ee. You might not know that if you haven't raised them. Check earlobes, on our ee white earlobes = green eggs.
I had a girl, she was 3/4 BO and 1/4 EE. I called her EE because she had green legs and laid green eggs, however she LOOKED like a green-legged BO with a little bit funky comb. I looooved her and she disappeared without a trace less than 2 weeks after she started laying