Anyone had an employer change the dress code on them after they'd started working there?

The board of the non-profit I work for implemented a new dress code. I know the board members and can easily see who wrote the dress code as it strongly caters toward clothing that is equally casual but more age appropriate on someone in their 60s and so far isn't being enforced universally : (

I don't have a problem with a dress-code per say, but adopting a new one in the middle of a season is a bit rough. I also am rarely seen by the public, work in extreme temperature and activity conditions, and often get dirty at work and need washable items.