Employment Law Questions? Ask an Employment Lawyer.
What state is this in?
If a company has any policies which are required to be followed by a company (for example, many companies may have policies but they are up for "discretion" whether or not they are used sometimes) and the company violates those policies, then an employee may sue for a failure to abide by those policies if an employee feels that failure caused them a harm. If "favortism" or such treatment is not, however, discriminatory or against company policies then there may not be much that may be done as, unless the act is otherwise illegal (as when it causes OSHA violations or discrimination for example) then such behavior is not illegal normally.
Where dicrimination is involved, which includes the denial of opportunities, advancement, pay, benefits, and others things at work due to race, gender, age, race, color, national origin, religion, disability, (and a few others depending on state law) then employees may file complaints with or seek more information or an investigation from the U.S. Equal Employment Opportunity Commission (whose NC offices are listed here) or hire an attorney to help them prepare and file a suit against the employer and employees involved.
Based on that discription, the different treatment based on race, those who are involved may have a good case and should speak to an attorney to obtain assistance in pursuing claims and in helping them deal with the employer's actions.