The red color of blood comes from protein hemoglobin, while ripe strawberries, red apples and reddish autumn leaves are colored by anthocyanins.Red pigment made from ochre was one of the first colors used in prehistoric art.This is the principle that is used to make all of the colors on your computer screen and your television.For example, purple on a computer screen is made by a similar formula to that used by Cennino Cennini in the Renaissance to make violet, but using additive colors and light instead of pigment: it is created by combining red and blue light at equal intensity on a black screen.
Red, green and blue light combined together makes white light, and these three colors, combined in different mixtures, can produce nearly any other color.
The remaining reddened sunlight can also be scattered by cloud droplets and other relatively large particles, which give the sky above the horizon its red glow.
and these two types of lasers were widely used in many scientific applications including holography, and in education.
The Ancient Egytians and Mayans colored their faces red in ceremonies; Roman generals had their bodies colored red to celebrate victories.
It was also an important color in China, where it was used to color early pottery and later the gates and walls of palaces.