Hey, yeah I know hum it isn't really that obvious. But when you're black you are in the "untruth", then you become white and you are "stuck" in the "Truth". That's why at the begin, the game tells you "when you know something you can't forget it" because once you're in the Truth you can't go back in the Untruth. So the game lies to you by showing you a sort of false level. (Poooof mind blow).
In fact it all should've been told with the text below but I preferred to concentrate my self on designing the levels.