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
Orange (colour) while those in Europe were either white or red. Dutch farmers bred a variety that was orange; according to some sources, as a tribute to the stadtholder of Holland and Zeeland, William of Orange. The long orange Dutch carrot, first described in 1721, is the ancestor of the orange horn carrot, one of the most common types found in supermarkets today. It takes its name from the town of Hoorn, in the Netherlands. Orange is traditionally associated with the autumn season, with the harvest and autumn leaves. The flowers, like orange fruits and vegetables and autumn leaves, get their colour