As said already, unless a parent is grey you can't get a grey chick. So, are you sure the Dad isn't grey green? Take a look at the feathers opening by the tail, they should show body colour pretty soon.
Blue is great with me I've had three clutches before these and all green! My Ebe (In my profile) is THE sweetest bird and my only tame and talking bird. So I have nothing against green birds Thanks for the help!