Some thoughts from my recent interview:
Out of 16-ish women, only one was not wearing a matching suit. Pant suits were most popular, followed by skirt suits. Only one person was in a dress suit. They did not stand out at all for being the only person to do so. Black and navy were quite popular, with a couple of grey suits tossed in the mix. I saw a few blouses that, while cute, were a bit too low cut for the nature of the day. I did notice that many of the women in skirt suits had issues with the skirt constantly twisting around and spent a lot of time worrying about it. Most women with long hair wore it completely down and either curled or straightened, a few had their hair partially up, and only a couple had their hair up completely (ponytail, bun, etc). Most women wore flats. A few wore pencil heels and seemed to regret it at the end of the day, as they were wobbling quite a bit! It was about 50/50 in terms of wearing pantyhose with a skirt suit. Most wore makeup, a few did not (although I would argue that they did not look out of place).