80s Trivia: Which of these colors was not on the original Rubik's Cube?

Who doesn't remember the Rubik's Cube?  The addictive toy first came out in 1974 but exploded onto the scene in 1980 and became an instant smash.  The original cube, of course, consisted of six colors.  The goal was to have all of the colors on the same side.

So, here is today's trivia question off of Pocket Trivia: 80s Trivia - Which of these colors was not on the original Rubik's cube?  Red, White, Purple or Orange?