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) philosophy of ancient China, orange was the colour of transformation. In China and India, the colour took its name not from the orange fruit, but from saffron, the finest and most expensive dye in Asia. According to Confucianism, existence was governed by the interaction of the male active principle, the "yang", and the female passive principle, the "yin". Yellow was the colour of perfection and nobility; red was the colour of happiness and power. Yellow and red were compared to light and fire, spirituality and sensuality, seemingly opposite but really complementary. Out of the interaction between the two came orange,