- External reference: https://en.wikipedia.org/wiki/Metamerism_(color)
Metamerism (color) - Wikipedia
metamerism is a perceived matching of colors with different (nonmatching) spectral power distributions. Colors that match this way are called metamers.
human eye contains only three color receptors (three types of cone cells), which means that all colors are reduced to three sensory quantities,
Metamerism occurs because each type of cone responds to the cumulative energy from a broad range of wavelengths, so that different combinations of light across all wavelengths can produce an equivalent receptor response and the same tristimulus values or color sensation