Depends on your coloring? Not necessarily. Everybody looks good in navy blue. The question becomes one of which shirt to wear and what tie to choose to set off your beaming face.
Grey seems more patrician, although I have no evidence to back it up. And at one point if a man owned only one suit, chances are it was navy serge.
Of course we’re speaking of worsted fabrics. Woolens, tweeds, flannels of all sorts are inherently more casual and that’s a different post.
Think instead of your coloring. If you look best in blue shirts, a grey suit will set them off better. If white is your go-to, the blue suit is a natural choice and presents to the world a dark column relieved by a sober tie.
Then too, we have the question of your wardrobe of ties. Do you favour ties with a primarily blue background?
What about shoes? Browns in suede and polished calf look fine with greys. Oxblood and black are the choices for navy.
Either suit is …. errr … suitable for business and all but semi-formal and formal affairs. Earth tones, lighter blues and greys. That’s where the fun begins.
So are you a blue or grey?