I asume you are asking about visible light. So, here is the answer:
The visible spectrum is the portion of the electromagnetic spectrum that is visible to and can be detected by the human eye. Electromagnetic radiation in this range of wavelengths is called visible light. A typical human eye will respond to wavelengths from about 390 to 700 nm. In terms of frequency, this corresponds to a band in the vicinity of 430–790 THz.
The spectrum does not ontain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink or purple variations such as magenta are absent. Colors containing only one wavelength are also called pure colors.
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