I started off by spraying the whole thin in Army Painter Ultramarine Blue. I've tried a different method of painting this time; instead of completing one colour at a time, I base-coated all of them.
To ensure I painted neat metallics, I used masking tape to cover up the edges I wanted to keep blue, then went to town with a big brush, painting on a black undercoat, and a Leadbelcher base-coat. I'd say that masking method was more or less a success. Not perfect, but far better than other methods. and it vastly speeds up the process, even when you factor in the time to mask the areas off.
I'm currently currently highlighting the blue areas with Calgar blue. I'll follow this up with with a 50/50 mix of Calgar Blue and Vallejo Glacier Blue. Once that is done, I'll go over the areas in black, to mark out battle damage I'll paint later in silver.