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
Judo in Canada (2011), Raymond Damblant (2012), and Hiroshi Nakamura (2012). Eleven Canadians are ranked "hachidan" (eighth dan), twenty-seven are ranked "shichidan" (seventh dan), and approximately 85 others are ranked "rokudan" (sixth dan). The names of the ninth and eighth "dan" holders are listed in the tables to the right. A typographic dagger () follows the names of those who are deceased. A registry of approximately 5000 black belts ranked "shodan" (first "dan") to "hachidan" (eighth "dan") in the years 1946–1997 is included in Glynn Leyshon's book "Judoka: a history of Judo in Canada". Canadians have won five Olympic medals in Judo since