DO IT! STICK IT TO THE MAN! Show them that your attire doesn't impact your ability to be a kickass employee. If you ever decide to wear black pants, I would at the very least, wear nice slacks. Wearing some skinny jean nonsense, I would consider inappropriate since the idea is to have some sort of professional outfit.
I wear black pants all the time, though I'm only a TM. It's never been a serious issue, but that could be because I live in California. The only time it's brought up is when (ironically) a new ETL comes to the store, and decides to talk about the dress code. I once had an ETL ask me about getting khakis, while in my peripheral vision, there was a poster right behind her with visual examples of the dress code, one of them being black pants. It even says, "Khakis are preferred, but any solid color pant is acceptable."