Well my opinion,
part - prefer gray or white - reason
background - gray - because of better contrast between character vs background.
eyebrows - none - both need to be thinner and more uniform.
nose - none - both need a retouch.
ears - none - both need to be smaller. i wouldn't mind if the ears would be completely hidden with that hairstyle.
face - white - grey square jawline is making the character look a bit to male.
lips - gray - mainly because white upper lip looks a bit to thin to me.
neck - gray - though both are kinda tall and the trapezius muscle is to flat; the neck straitening in white needs to be more uniform not just a weird bend though i prefer this approach it needs a better implementation and why i end up voting gray in this category.
shadows - white - mainly because at least in that one the left half of the face doesn't have shadow, i would also try a lighter tone for that shadow and perhaps a different color, to me as it is looks bad.
Considering the rest of the body is pretty much equal in both i will refrain from sharing my opinion on those parts.
On another aspect if the goal is the character cosplaying as X-men Storm it's fine though if it's Storm you could get rid of the eyes iris.