Painting white

It seems like a good moment for a new post!
I am now making an aspiring champion for the first of my chaos space marines squads (one of them was introduced here). It still needs some finishing paint drops and of course some missing parts. He's going to have a converted backpack - similar to those owned by GW's noise marines.
I probably should also repaint the coat of arms - it does not seem to fit into chaotic style at all.

I've decided to use this miniature to experiment with painting white clothes (and by white I mean white, not a very bright brown). It was tricky but I think that the effect is not bad. What do you think?

I am awaiting your comments! Please do share your opinions!

Cheers!