First off, let’s agree on the fact that it is okay for men to wear gray dress shoes. I realize that it is not acceptable in all settings. I think I’ve only seen another guy wear them once or twice in the wild. But just because something is not done often, does not mean that it is not okay. And in fact, the absence of gray dress shoes is likely the most legitimate and substantial argument against them. So like just about anything, you have to be comfortable wearing gray shoes and you have to know whether it is appropriate to do so in whatever workplace or social setting your are in.
There are other arguments against gray dress shoes. An argument saying that gray dress shoes lack formality is one that lacks substance. Gray dress shoes, at least those in darker shades are actually quite formal. Not as formal as black or dark brown dress shoes but certainly more formal than light brown dress shoes. Largely because of their dark color and that gray is thought to be more formal than brown. Furthermore, keep in mind that even the least formal of dress shoes in gray will still be more formal than the most formal casual shoe (sneaker, driving loafer etc).
And of course there will be those who say that gray shoes cannot be mated with most colors of suits and trousers. Which again, is a false argument. Refer to my chart on What Color Shoes To Wear With What Color Pants for a bit more on that. But in fact, gray shoes can go with most colors of pants and suit. I have included photos of two of the more common and easy to do pairings; gray shoes with a gray suit and a navy suit.
Yes, I am sure there are other arguments against gray dress shoes (the same arguments could also be used for navy dress shoes, which I am also a fan of), but I think I have addressed the three most common ones. To my eyes the shoes go quite well with the gray and navy suits. And to my knowledge, my wearing of gray shoes has not offended the eyes of others. At least, that is to say, they have received many positive comments and no negative ones.
As much as I am a fan of gray dress shoes, I wouldn’t advise making an investment in gray dress shoes until you have a solid rotation of black, brown and burgundy shoes. So perhaps these would be the 6th man in your shoe wardrobe. As I said before, it all comes down to whether or not you can make the shoes work for you and whether or not you are comfortable wearing them. If you are not, then I suppose that’s that. But if it is something you could see yourself doing then gray shoes could be a great way to grow your personal style and wardrobe.