Indigo Indigo is a color between blue and purple, and cyan in Indigo Purple is a color between green and blue. Indigo violet and cyan violet not only have great color differences, but also have different frequency ranges and color values in the spectrum. Only red, orange, yellow, green, blue and purple are the most common sayings in China.
Red represents enthusiasm, celebration, passion, etc. , give a person a kind of very solemn and steady feeling. Now many big occasions use red; Orange is a warm color, representing warmth and friendliness. Yellow is the most vivid, it represents gorgeous, bright and lively; And green represents life, agility and gives people the breath of spring. Blue is a cool color, representing calmness and reason. Indigo represents generosity and dignity, giving people a very sophisticated feeling; Purple represents elegance and fantasy, and is also a very popular color.
The formation principle of rainbow:
Rainbow is formed by the scattering and reflection of sunlight on spherical water droplets in the air. When sunlight enters the water drop, it will be incident at different angles at the same time and reflected at different angles in the water drop. The reflection of 40 to 42 degrees is the strongest, which produces the rainbow we see. When this reflection occurs, sunlight enters the water drop, refracts once, and then reflects on the back of the water drop.
Finally, when leaving the water drop, it refracts again, and refracts twice after one reflection. Because water has a dispersive effect on light, the refractive index of light with different frequencies is different. The refractive index of red light is smaller than that of blue light, and the deflection angle of blue light is larger than that of red light. Because light is reflected in water droplets, the spectrum seen by the observer is reversed, with red light at the top and other colors at the bottom.
So the heights of rainbows and neon lights are different, and the hierarchical order of colors is just the opposite. Rainbow means that light is refracted twice and reflected once, while neon means that light is refracted twice and reflected twice.