My 5-year-old Son's Rosa Parks Question

In advance of Martin Luther King's birthday, my wife and I have been checking books out of the public library on Dr. King's life, and the civil rights movement in general. Our local elementary school has certainly dedicated a significant part of its teaching year to the civil rights struggle.

My wife is Caucasian, so our children are half-Asian, but we have always taught our children, Katharine and Allen, that they are persons of color, even though they are only half. Their half-Asian status came up last night because my wife was reading to our 5-year-old son Allen about Rosa Parks. He learned the rule in those days that black people were supposed to sit in the back of the bus, and white people sat in the front. Aware of his half-Asian status, Al thus asked, "does that mean that Katharine and I would have had to sit in the middle of the bus?"