The usual colors for shoes in the West are black and brown, with dark red finding an occasional place. Though no generalization is ever entirely accurate, the French have been known to add navy blue and dark green to that list, as has the author of Red Flying Pig, a low volume of publication Chinese language weblog. In the photos, the author's John Lobb (Paris) Woodcote oxfords in dark blue.
Blue of course is an interesting choice of color because at night it will look like black under artificial light, and evening is a time when these shoes would be at their best. Other than the color, they are nearly as formal as shoes can get. That makes me think of pairing them with suits, but personally I would be more comfortable wearing them with cotton or linen during the day, and that in turn makes me wonder if the color might not be more useful in a more casual design. Monkstraps perhaps.
Beautiful things nonetheless.
Photos: Red Flying Pig