This sounds a little bit like a "he said, she said" type of situation. You won't get far with suing them for slander. Your employer would have the right to terminate you based upon these types of allegations so wouldn't have a claim against it. Your slander claim would be limited to the other employees and they are unlikely to have assets to collect against even if you win on such a claim. Your best bet may be to contact your HR representative to bring them up to speed on what is happening to ensure that the higher-ups have your side of the story.
I agree with my colleague. Anytime an employee complains to the employer about racial harassment, the employer has a mandatory obligation to investigate and take corrective action, which can range from a warning to termination, whatever is effective to prevent further harassment. As the person who is accused, your actions are very limited. Of course, you should cooperate with the employer and provide any evidence, including the names of any witnesses who might have some information to help get to the truth.
Yes, if the employees make false accusations against you to get you fired, you could sue them for slander. But you still must prove they lied and even if you win and are awarded damages, you must find a way to collect from them. However, you should consult with an experienced lawyer in your area to review what options are available to you.
They say you get what you pay for, and this response is free, so take it for what it is worth. This is my opinion based on very limited information. My opinion should not be taken as legal advice. For true advice, we would require a confidential consultation where I would ask you questions and get your complete story. This is a public forum, so remember, nothing here is confidential. Nor am I your attorney. I do not know who you are and you have not hired me to provide any legal service. To do so would require us to meet and sign written retainer agreement. My responses are intended for general information only.