Thanks all!
@Montka: I'm afraid I really don't recall the colours on the flames and not really the exact colours of the face as well. I seldom work with formulas so unless I write the colours down it's difficult to remember, I just mix until I'm happy.
For the flames.. well looking at it now I'd just mix orange with yellows for the main colours, more yellow and adding white for the lightest parts. Adding reds and blacks for the darkest parts. I also have added some sparks with white sparingly. It was important to have some darker parts in the flames so that it didn't look entirely opaque, I would push that even more next time, but it's hard to make it look good from all angles.
I think I did a basecoat with khemri brown on the skin and the used graveyard earth that I mixed with a bit of red for a fleshier midtone. I mixed in more reds for the cheeks and some other parts and the final highlights were done with vallejo ivory. I most probably glazed some with greens, greys and browns as well.
