Painting a 109 engine

I have a 1973 Series 3 109 Carawagon that i'm completely restoring.I have the engine out and i want to paint it before it goes back in.It's a mid green colour.Can anyone tell me what the colour name or code is?Where can i get the paint?Does it have to be high temperature paint?Are the block,head,rocker cover all supposed to be painted?
I would like to keep it as original as possible.Any info would be greatly appreciated.

I should have added that it's the standard 2.25 diesel engine that's in it.

block is duck egg blue ,head satin black, rocker box plain aluminum

Thanks for that.It's all painted the green colour at the moment but it must've been changed by someone.I take it that duck egg blue would appear to be more of a green in appearance?Maybe it's a completely different colour that someone has put on mine!

yes light greenish ,military engines were all painted duck egg blue,which is why you see so many often like that but as std only block was all aluminum was unpainted and bolt on parts including head are black

Ok,thats a great help.I'll put it back to the standard way.

if its a military wouldn't it be better to lpaint it the one colour? my s1 has a military recon engine and that's all the light greenish colour

The engine in my Ex-MoD 2a 109 has a red block and cylinder head? its 2.25 petrol