Does the right to refuse service allow discrimination?

The law says Any private business can refuse to serve anyone they choose. However, they cannot discriminate people based on , race, religion, orientation, etc. But if there was a whites only restaurant today could a black still be arrested for tresping? And if proved discrimination would all pile up charges such as evading arrest or aulting an officer be dismissed and expunged? Or would the black still get charges even though there are discrimination laws? Which law acts first, discrimination or tresping?