There are 34 kinds of red.
Mainly red, vermilion, purples, crimson, pink, orange, apricot, pink, peach, rose, rose, alizarin, earth red, rust red, light pearl red, shell yellow red, orange red, light pink, salmon red, scarlet, bright red, cardinal red and Burgundy wine.
Red is to stimulate the observer's vision through energy. The color at the end of the low frequency in the visible spectrum of electromagnetic waves, with a frequency of 38-48 THz (corresponding to the wavelength of 78-62 nm in the air), is similar to the color of fresh blood. Ordinary people cannot see electromagnetic waves with a frequency lower than red, and such electromagnetic waves are generally called infrared rays. Physical characteristics
Red has the lowest frequency in the visible light band of physics, and it is this property that makes it have many unique properties that are different from other colors.
Red has the lowest frequency, which means it has the longest wavelength, and the longest wavelength means it has the strongest diffraction ability and the strongest ability to cross obstacles. Therefore, when the warning light uses red light, it can still be effectively observed even in bad visual conditions such as foggy days, which is the fundamental reason why the traffic lights use red as a stop sign.
Red light has the lowest light frequency and the longest light wave, which causes it to form a larger image than other colors when it is focused on the retina of the eye, so if there are two objects of the same size in front of you, the red object always looks bigger than the blue one, even if the brightness of red and blue are exactly the same.
what are the above references? Baidu Encyclopedia-Red