For the human eye, only the wavelength range of approximately 380 nm to 780 nm is visible. Below that is the UV range and above it is the IR range, which cannot be perceived by the eye.
The wavelength of the LEDs, when the light is on and based on 20 mA, is:
The color space established by the CIE (International Commission on Illumination), in the form of a horseshoe shape, was originally established in 1931. It is based on the color perception of the human eye and is recognized as a reference color system. It applies to monochromatic light with wavelengths between 380 nm and 700 nm.
The CIE color space model has its origin in the three-color model. The three-color model states that all other colors can be mixed from the primary colors red, green, and blue. In the CIE color space horseshoe, the triangle of the three-color model is often still included.