I have it on good authority (mine) that there are only nine colours - red, yellow, orange, green, blue, purple, white and black

Black and white aren't colours...except sometimes they are. :^O http://www.colormatters.com/color-and-design/are-black-and-white-colors

Did you know that the technique to make true black glass was lost many years ago, and now they just make it from dark purple? Tecnhically, I could have an INAD case opened against me for describing black (looking) glass beads as black. 😮