I was thinking... the white section on the face/nose area... how would that look if it was painted black?
It'd probably look pretty cool, but I think given the concept that this is some kind of "test pilot" gives room for more of an experimental look.
I'd even be comfortable with more markings on the white area... orange or bright blue caution stripes or a simple imperial numeral to designate which pilot we're dealing with.
If you made it all black, he'd probably come across as a battle-ready soldier (and a good one, BTW).