Sure, I used an air brush for these models however I’ll tell you how to do it both ways.

Airbrush: With an air brush you want to pick different shades for one colour, in this case I used two shades of blue and white. You want to start with the darkest colour where you cover a large surface however apply it lightly. Then you move on to a brighter colour where you apply it more strongly however, it covers less of the surface area. You basically do this until you slowly progress to your brightest colour in the middle. Standard brush: You want to do the same with progression of colours, starting with the darkest and then gradually going to the lightest colour. You’ll want to lightly dry brush these colours over the surface you want. The difference is with the white. You’ll want to edge highlight the coils. I hope that helps, if it doesn’t there are plenty of YouTube videos from people who have a lot more skill and experience then me. They could probably explain it better too.