The colour Red has the highest wavelength in the visible spectrum, i.e. about 650 nanometers (nm).
The electromagnetic spectrum which emanates from the Sun has the full range of light. But our can see only a portion of it. This visible range of wavelength (approx 400 nanometers to 700 nanometers) is called the visible spectrum.
The visible spectrum of the electromagnetic spectrum is known as visible light. The violet
The violet colour has the shortest wavelength while the red colour has the longest wavelength
You may recognise the visible spectrum from the colours of the rainbow.
A rainbow has 7 colours. It has colours ordered from lowest to highest wavelength.
- Violet – 400 nm
- Indigo – 445 nm
- Blue – 475 nm
- Green – 510 nm
- Yellow – 570 nm
- Orange – 590 nm
- Red – 650 nm
The wavelength of the colour “white” ranges from 400 to 750 nanometers.
There are many wavelengths in the electromagnetic spectrum the human eye cannot detect like ultraviolet (10 nm to 400 nm) and infrared ray (700 nanometers to 1 millimetre).