What are the seven colors of the "seven colors"?

The most common Chinese term is: red, orange, yellow, green, cyan, blue and violet. In the West, it is: red, orange, yellow, green, blue, indigo and violet, named after the scientist Isaac Newton, who broke down the seven primary colors.

When the sun's rays hit the water droplets in mid-air, the light is refracted and reflected, forming an arch of seven-color spectrum on the sky, from the outer circle to the inner circle of red, orange, yellow, green, blue, indigo, violet? There are eight colors in the rainbow. In fact there are countless colors in the rainbow, for example, there are many other nuances of color between red and orange, but for simplicity's sake, so only seven colors are used as a distinction.

Expanded Information

Rainbows are caused by the dispersion and reflection of sunlight on small, nearly spherical droplets of water in the sky. When sunlight hits a water droplet, it enters at different angles and reflects at different angles within the droplet. The strongest reflection is at 40 to 42 degrees, resulting in the rainbow we see. When this reflection is caused, the sunlight enters the droplet, first refracted once, then reflected at the back of the droplet, and finally refracted once again when it leaves the droplet, totaling **** after a reflection of two refractions.

Because water has a dispersion effect on light, the refractive index of different wavelengths of light is different, the refractive index of red light is smaller than that of blue light, and the angle of deflection of blue light is larger than that of red light. Because the light is reflected within the droplet, the observer sees the spectrum in reverse, with red light at the top and the other colors at the bottom.

References:

Baidu Encyclopedia: Rainbow