Pretty much, yeah. Segregation in the US was still very much de facto, particularly in the southern states, even if it wasn't de jure. Black musicians were often not allowed to play in certain halls, or if they were, were made to enter through the servant's entrance out back, couldn't use the washrooms, eat the food, mix with the audience, or stay at the hotel.

Sammy Davis Jr famously describes his experience in playing Vegas, and having to enter/exit through the kitchens, not being fed, and having to stay in hotels outside the city that catered to a Black clientele. This only stopped when Sammy became part of the Rat Pack, who threatened to pull their act from Vegas if they didn't allow Sammy to stay there.

Dorothy Dandridge faced the same issues in Vegas, and throughout the south. Can't mingle with guests, stay in the hotel, use the pool, the washrooms, enter through the back, stay on the outskirts of town.

Now, that being said, these establishments were white only, so it was white clientele that paid big bucks to see these black artists, who gained a lot of popularity in the 50s and 60s, despite being forced into the sidelines offstage.