New employee comes to work wearing blue jeans and says "I wasn't sure if it's okay to wear blue jeans."
If you aren't sure, it seems to me that it's better to err on the side of caution and wear business-type attire, but I guess not everybody's brain works that way!
Speaking of dress codes, most businesses around here have business casual dress codes but I've been observing lately that there are some people who still manage to look too casual, even if they are wearing clothes that fall within the rules. There are a few women who wear basic slacks and blouses but always look so rumpled or unkempt, they may as well be wearing sweats or pajamas. If you mention it to them, they protest that their clothes fall within the guidelines, and it's hard to have to tell them that it's not the clothes per se, it's how they are wearing them and their general grooming. I've always been surprised at the fact that you might have to mention to a 40-year-old woman that it's a good idea to at least make a pass at their head with a hairbrush in the morning before coming to work.