why are we able to see colours not included in vibgyor?

Color derives from the spectrum of light (distribution of light energy versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors.Typically, only features of the composition of light that are detectable by humans (wavelength spectrum from 380 nm to 740 nm, roughly) are included, thereby objectively relating the psychological phenomenon of color to its physical specification. In brief, the colour depends on the wavelength which can vary greatly containing vibgyor as well as all the colours that can be obtained by mixing of these colours or as depending on length. So we are ableor.gyb to see colours not included in vi