<P> Indigo is a deep and rich color close to the color wheel blue ( a primary color in the RGB color space ) , as well as to some variants of ultramarine . It is traditionally regarded as a color in the visible spectrum , as well as one of the seven colors of the rainbow : the color between purple and blue ; however , sources differ as to its actual position in the electromagnetic spectrum . </P>
<P> Indigo is a deep and rich color close to the color wheel blue ( a primary color in the RGB color space ) , as well as to some variants of ultramarine . It is traditionally regarded as a color in the visible spectrum , as well as one of the seven colors of the rainbow : the color between purple and blue ; however , sources differ as to its actual position in the electromagnetic spectrum . </P>
is indigo a shade of blue or purple
is indigo a shade of blue or purple
blue
blue