[Boy Blunder]

@En Sabah Nerd - the costume choice is likely due to the fact that this version has been used in media outside the comics - specifically, this is the costume MK wears in his Ultimate Spider-Man animated appearances, as well as the Contest of Champions and Future Fight mobile games. As we've seen throughout the current iteration of the line, Hasbro likes to go with looks that will appeal to a wider audience, and will pepper the comics choices with ones inspired by external media (IE Taskmaster, Iron Skull, etc). This way, people who aren't specifically comic fans will still recognize this as MK.

Also, it might've been easier to sell the figure (both to stores and to consumers) when he's not a big block of white.

Lastly, the whole Mr. Knight look seems much more suited for a Select release, IMO.