Leggings over pantyhose? Yes, yes, yes!

Ask an average modern woman what she thinks about wearing pantyhose under leggings and she'll either tell you "no way in hell" or she'll give you a perplexed look and ask you "why?". Believe it or not however, for a while during the late 80s/early 90s, wearing pantyhose under leggings was quite fashionable in certain parts of Europe. Young women and girls hardly wore leggings without pantyhose under them – for what reason, I have no idea. Fashionable legging lengths were somewhere midway between Capri length and ankle-length, which meant that there was a certain area of skin shoving above the ankles. The pantyhose were supposed to cover up those areas, while making the legs look even better.
The truth is, wearing black pantyhose under shiny black leggings looks good indeed. The hose can be simple or patterned but they need to be sheer (and probably shiny too) in order to go well with the leggings. There seem to be certain color-codes when it comes to wearing pantyhose with leggings.

Black definitely goes well with black, however it doesn't seem to work with white, silver, pink or any of the other colors. Various shades of tan work well with just about anything, except black. Pantyhose which are the same color as the leggings usually work just fine. White is interesting because it doesn't quite seem to work well with anything but white leggings.
Why did women wear pantyhose under their leggings? Try some shiny sheer black pantyhose with shine black leggings and see if you like the look (and the feel). The only reasonable explanation would be that they did it for that look. For some people, there seems to be something appealing about it.
Doing it on account of the cold could also be an explanation. Putting on panty hose under the leggings definitely increases thermal insulation, directly impacting the comfort level of the wearer if the temperatures call for it.
Still, many women apparently wore the panty hose/leggings combination in warm weather too.

If you're one of the few who enjoy showing a little bit of nylon under the bottom of your leggings, there are solutions that don't necessarily involve the wearing of hose AND leggings. There are nylon ¾ socks out there, which look exactly like pantyhose. When worn with leggings, no one will ever be able to tell that you're not actually wearing pantyhose. There are even patterned nylon socks out there that will create the impression that you're wearing black fashion pantyhose with your leggings. This way, you'll be able to show nylon under your leggings, while avoiding the thermal discomfort created by the layering of nylon hosiery.