How is the idea of dream deferred related to issues of colour and racism in the context of America ?

In Langston Hughes's famous poem "Harlem" (sometimes referred to as "Dream Deferred"), the speaker ponders what happens to a dream when it is delayed or put off. We don't know precisely what dream it is that the speaker refers to, as it is never explicitly stated in the poem, but the poem's original title of "Harlem" provides a significant clue. It seems likely that the dream referred to is the dream of racial equality, a dream which came dramatically to the forefront of American politics in the mid-twentieth century. Hughes was one of the preeminent poets of the Harlem Renaissance, and Harlem was a community that was primarily comprised of African Americans. The speaker ponders what will happen to a dream deferred, and the final possibility—that it will "explode"—seems the most compelling because it makes use of the only metaphor in the entire poem (which is full of less-powerful similes), because the line is set apart on its own, and because it is typeset in italics. This seems to imply that the effects of a dream deferred, especially the dream of racial equality, will be volatile and violent, like a bomb. It will not only affect the would-be dreamer but entire communities. In other words, the effects of continued racism will be farther-reaching than just African American communities; white America must acknowledge the dream.