I live in California and my wife was just told that she needs to abide by a dress code because she is "face of the office". She is not a front desk receptionist and nothing has been said to her about her dress in the almost 5 years she has worked there. She was told that this new dress code is only applicable to her. Is this legal??

The fact that it has not been addressed in the past does not mean it can be addressed now. The company does have the right to set what it considers appropriate dress, especially for employees who meet the public.

What is the problem with the "dress code" as presented?

My wife does not work in the front office. The problem with the dress code is that it is only applicable to her and no one else in the school district. Individuals with direct public interaction do not have to abide by the same dress code.

Unless she is being singled out BECAUSE OF her race, religion, national origin or other characteristic protected by state, federal or local law, it is legal for her employer to tell her that she has to follow a specific dress code, even if no one else has to follow it. It is a myth that all policies have to apply equally to all employees; the law only says that differences in application cannot be BASED in a characteristic protected by law.