BUT WAIT!
There is an easier way to get that same look!
**Credit to Mike French over on HERESY 30k**
Do the metallics as described above
Then do a light layer of clear green from the top
Cover that with clear blue until the color suits your taste
Wash with guilliman blue and you are done
This guy was done doing
FW's scheme step by step
while this guy was done with the "improved" method
I find the second way to give much smoother results, mainly because there are less steps, and also that extra layer of silver near the end can cause an undesired look as seen in this picture
you can see the "flecks" of silver showing through much more. just doesnt look as good
IMO