Dedicated to live forever and have peace wherever.
When a light ray is beamed into a right angled triangular prism the light is fractioned between 40° - 42° to reveal seven distinct colours. Newton (1672) first degreed this rainbow for five colours; red, yellow, green, blue and violet. Only later he derived orange and indigo to match the colours to a musical scale:
C-D-E-F-G-A-B or C-B-A-G-F-E-D.