Structurally black is favored over white because the reader is presented with many different descriptions that use black within the first paragraph. Toomer creates a world that is shrowded in darks and blacks. This establishment seems to function like clockwork until white comes into the picture. White is usually seen as a sign of purity, thus the reason many use it as the color of their wedding dresses. Toomer plays with this meaning by having white signify impurity because whenever John is thinking of Dorris sexually he is being spotlighted by a white pillar of light. This makes white subordinate to black within the story because this light has negative effects on Dorris and the production of the play. The white light is even, if you will, defeated by darkness and shadow when the keyboard clanks. Ultimately, it is the shadow and black that finishes the story when Toomer shroudes his characters in shadows in the last paragraph.
Even though black seems to be favored as the favored piece of the binary, it is challenged by white. First off, the idea of white, or a ray of light, coming into and invading and all black establishmnent is, in itself, a challenge to the black domination. Toomer even has his characters challenge the fact that they are black. The director tells Mame and Dorris to focus on the dance and Mame lashes back with her line, "Go to Hell, you black bastard." Mame, does not refer to the director with respect, but instead insults him by calling him a bastard. She goes a step further by coupling her insult with the description of black. It can probably be assumed that Mame is black since she is working as a dancer at the Howard Theater, so it is interesting how she decides to disrespect the director with her reference to his skin color. Besides this white/light challenges dark/shadow during the dream sequence at the end of the story. Dorris is described as wearing a "loose black gown" and John is described as wearing a "collar and tie colorful and flaring." The bright colors take advantage and dominate black in the sense that Dorris gets manipulated by John during this section.
Looking at these few examples, and understanding that black is favored over white in "Theater," one receives a different definition of the white/black binary. Toomer's story challenges the cultural favor of white over black. He establishes black as the status quo in his world by describing everything with black or shadow. By using white to challenge black, the story gives insight into how the African-American community feel about the imposed laws, culture, living spaces, etc. that are given to African-Americans from the "white" or culturally dominant ethnicity.