I disagree with using blue for stormtroopers. Their armor is so glossy and shiny, it doesn't really give off a glint of a blue tinge. One of the reason why they look so iconic is they are SO stark white and black.
It's not to say you can't, just that it's a stylistic choice based on what you imagine him being surrounded by. Case in point, the next two images.
Their helmets in the movie scene there kind of have a slight blue to them, because it's so reflective of the light. The fine art piece at the bottom is just ramping that up.
But, typically, it's going to be more stark white with grey/black shadows. Color will happen based on the surroundings once you add a gloss finish.