Theater can be seen in a historical light. Many of the references, such as the setting (the African-American section's Howard Theater), John's allusion to "beautiful" black women who resemble white women, and the term dictie all indicate a socially charged time in history. If the text is seen in this manner, then the signs of light and shadow become much less clear. Perhaps John, although clearly a black man in the story, is a metaphor of the white race, forced to face accepting the black race (i.e., Dorris). Perhaps the light and shadow mark a conflict of acceptance and rejection. The light, on the one hand, portrays the average white man, tempted to accept African Americans. It is his desire. His intellect, however, as portrayed by the shadow, could opposed to this desire, reminding the man that social constructs of the time would frown upon his decision.
And the conflict within Dorris, to accept John, could be seen as the black community reaching out to the white community, but, seeing a perceived arrogance, draws back in fear.
In addition, the logocentrism of the story suggests that light, or desire, is favored. Perhaps in the case of a white and black communities, this is true. But what about instances where this may not be true? What if, in the close reading of the story, the privilege should be given to the shadow? Perhaps the intellect, the decision to reject the other, was the correct one. After all, decisison based entirely on passion are sloppy and unreasonable. Perhaps the intellect acted as an impediment to a potentially regrettable decision.
There are many other parallels that can be drawn, but the signs of light and shadow cannot so easily be deduced, or so the deconstructionist would say.