Question: what are the colors that are not in the rainbow

title: Rainbow
text: The colour pattern of a rainbow is different from a spectrum , and the colours are less saturated . There is spectral smearing in a rainbow owing to the fact that for any particular wavelength , there is a distribution of exit angles , rather than a single unvarying angle . In addition , a rainbow is a blurred version of the bow obtained from a point source , because the disk diameter of the sun ( 0.5 ° ) can not be neglected compared to the width of a rainbow ( 2 ° ) . The number of colour bands of a rainbow may therefore be different from the number of bands in a spectrum , especially if the droplets are particularly large or small . Therefore , the number of colours of a rainbow is variable . If , however , the word rainbow is used inaccurately to mean spectrum , it is the number of main colours in the spectrum .