Kazuko has a beach ball. It is colored with 6 vertical stripes, in order: white, orange, yellow, blue,
red, and green. She spins the beach ball on the surface of the water in her swimming pool, and
she notices that the colors whirl by very fast. If the first color to go by is white and the ball spins
around so the 500 colors go by, what is the 500th color?