The app EatOkra provides a service.

The app provides a service to food businesses ("Business-customers"), by listing them in their app, and provides a second service to prospective customers ("Customers") that wish to buy food, displaying those listings to them.

Customers can be any creed.

Business-customers can only exist of one specific race.

Is this legal? Am I missing something or doesn't the civil rights act of 1964 disallow something like this?