I was working in the military. An office job at HQ so we had to use our parade uniforms. I was working nights one week and didn't have any clean black socks, I used white.
Around 8 in the morning I was walking up the stairs to leave and passed the Naval Admiral, who promptly chewed me put for wearing white socks and dress shoes.
Kind of surprised that you see that as weird. I served myself and would never dream of wearing the uniform improperly. Especially around stars and bars. HQs got nothing better to do than dress and appearance.
I have never understood the need for black socks when wearing dress shoes. Especially since the majority of sane people definitely aren't gonna look directly at your feet and complain about white socks. If it were different colors or patterns then I could see it, but otherwise I just don't get it at all.