The s RGB number for crimson is 220, 20, 60, which means that the red is slightly less intense and therefore darker, there is some green, which leans it toward orange; and there is a larger amount of blue, which makes it slightly blue-violet.
As a ray of white sunlight travels through the atmosphere to the eye, some of the colors are scattered out of the beam by air molecules and airborne particles due to Rayleigh scattering, changing the final color of the beam that is seen.
Modern surveys in Europe and the United States show red is also the colour most commonly associated with heat, activity, passion, sexuality, anger, love and joy.
In China, India and many other Asian countries it is the colour of symbolizing happiness and good fortune.
Bulls, for instance, cannot see the red color of the cape of a bullfighter, but they are agitated by its movement.
Today modern darkrooms usually use an amber safelight.
In the language of optics, red is the color evoked by light that stimulates neither the S or the M (short and medium wavelength) cone cells of the retina, combined with a fading stimulation of the L (long-wavelength) cone cells.
Primates can distinguish the full range of the colors of the spectrum visible to humans, but many kinds of mammals, such as dogs and cattle, have dichromacy, which means they can see blues and yellows, but cannot distinguish red and green (both are seen as gray).
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.
The red colour of blood comes from protein hemoglobin, while ripe strawberries, red apples and reddish autumn leaves are colored by anthocyanins.