This is the dad of the baby budgie I've booked. The mum is a double factor dominant pied light green (what a mouthful!) but I can't figure him out... What sort of a budgie is he please, o experts?

looks like grey green dominate pied golden face opaline, hence why the yellow goes into the body colour. I could be wrong xxxx

Thanks, I thought so too at first, but then got confused because a lot of his body looks just grey... not very greenish like other grey-greens. Like, he has grey-green patches (one obvious one on his chest) but most of his tummy looks proper grey. Now, if he was green pied, the base colour would be yellow, so the pure-looking grey patches confuse me...

he could be a y/f type 2 grey dominate pied opaline.

type 2 the colour runs into the body colour not golden face x

The terms YF and GF only applies to blue birds as all green birds have yellow faces. He does look like a grey green dominant pied. I do think he is also opaline. Could you post a photo of his back? It could be possible that the photo is off and he is a YF2 grey or something, but I really do think he is a green based bird.

Here he is from the back:

So then all the babies would definately be pied (since the mum is DF) and definately grey because that's dominant over normal, but *could* be blue-based pie if both the parents were split for blue, am I right?

They should all be pied. And you could get some blues/greys if they both are split to blue. The grey passed in will depend on if dad is single or double factor grey. Single will give you some grey greens and some non grey factored birds. If double factored, all chicks will be grey. All opaline chicks will be female. But not all females will be opaline. Unless, of course, mom is also opaline.