Orange (colour) colours on a television or computer screen), orange is generated by combining high intensity red light with a lower intensity green light, with the blue light turned off entirely. Orange is a tertiary colour which is numerically halfway between gamma-compressed red and yellow, as can be seen in the . Regarding painting, blue is the complementary colour to orange. As many painters of the 19th century discovered, blue and orange reinforce each other. The painter Vincent van Gogh wrote to his brother Theo that in his paintings, he was trying to reveal "the oppositions of blue with orange, of red
Gardner color scale the liquid. This procedure isn't extremely accurate due to variations of observers, illumination and to some extent the standards themselves. Gardner Color can also be measured by a dual beam xenon flash spectrophotometer, for example the ColorQuest XT. Spectrophotometers measure the percent transmittance of the product and automatically calculate and provide the Gardner color number using illuminant C and 2º observer. Gardner color scale Gardner Color Scale is a one-dimensional scale to measure the shade of the color yellow. Colors of transparent liquids have been studied visually since the early 19th century. Changes in color can indicate contamination or impurities