Color theory primary colors work at all is that the imperfect pigments being used have sloped absorption curves, and thus change color with concentration. A pigment that is pure red at high concentrations can behave more like magenta at low concentrations. This allows it to make purples that would otherwise be impossible. Likewise, a blue that is ultramarine at high concentrations appears cyan at low concentrations, allowing it to be used to mix green. Chromium red pigments can appear orange, and then yellow, as the concentration is reduced. It is even possible to mix very low concentrations of the blue mentioned and
Rank in Judo first five are colored black, 6th, 7th, and 8th "dan" have alternating red and white panels (dandara), and for 9th, 10th "dan" and above, the belts are solid red. In judo's promotion system as originally finalized by Kanō around 1926 there was no maximal dan rank, and judoka holding 10th dan would normally wear a red belt, but also could wear a white belt, the same color as the lowest kyū rank. However, since the highest dan rank reached in judo for a living person or conferred posthumously remains 10th dan, any judo dan rank higher than 10th dan is