Thanks Youli!
Actually, the purple on the cockpit is just the Humbrol Maskol. It dries as a semi-transparent rubbery gel which you can then peel away once you've painted over it. By sheer coincidence it is almost exactly the same colour as the purple I'm using for the starfighter's markings!
Looks kinda cool though, doesn't it? I'm sure Mace Windu would approve. Maybe I'll leave some on there when I finish. Comes off rather easily though...