From Vincente Minnelli's autobiography, I Remember It Well, 1974.
During my first few months at Metro, the only challenges were to my imagination. Lena Horne came to the studio at the same time, and my first assignments were to direct her musical numbers. Another director would do the rest of the film. Lena complained in her autobiography that because she was black, her many numbers were never integrated into the script. They could thus be cut out of the film if Southern distributors objected. This was, of course, contemptible. Could it have been only 30 years ago that we considered it daring to cast a black actress in a non-servile role? We were raising our puny voices for social progress. They should have been louder.
From Lena Horne's landmark 1981 one-woman show, excerpted in her interview with Ed Bradley, a snippet of which is accessible here.
They said to Max Factor, "Look at this woman. Look at her. Create a makeup to make her look more colored." That's a little something we used to call each other before we got straight. He said, "Okay." Okay, they'll do anything. And he went away, come back about two weeks later with a makeup they created for me. Named it Light Egyptian. Took this Light Egyptian and put it all over Ava Gardner. So I'm gonna tell you, I felt bad for a while. About 12 years.
And a beautiful tribute here, from Sheila O'Malley.