The secret to painting white is that you don't - paint (and shade) in light grey, and then highlight with (progressively lighter greys and then ultimately) white.

I use "white" as an accent colour for my guys, and my recipe for "white" is:

• spray of white

• layer with a couple of thin coats of Vallejo Light Grey

• recess shade of agrax earthshade

• tidy up with Light Grey again

• highlight with Vallejo Sky Grey

• Ultimate edge highlight on the sharpest points only in white - and even that is only on key parts like helmets (or key characters).

But if you looked at it, you'd guess the relevant bits were white.

When I was first starting miniature painting someone told me that if you're using white paint, you're almost certainly doing something wrong - and that's really good advice to follow. White is hard to thin well, doesn't cover, looks terrible when it's anything less than perfect, and you can't highlight it. Definitely avoid it and use light grey instead.