It happened suddenly and without warning. One moment Humanity was a spectrum of races, skin colors, languages and cultures and the next there was only...one.
Homo Sapiens had become homogenous. Everyone was now the same race, spoke the same language and belonged to the same culture. Even the world itself changed. As far as reality was concerned, Mankind had only ever been one race. Art, history and even the names of places were changed to reflect the new monoracial world. Cities from the old world had different names or had never existed at all. Everything had changed.
Everything that is except people. All humans, especially those effected by the change, still remembered the way the world used to be. After the natural shock of the change wore off they now faced the daunting challenge of a world where diversity had never existed.