Which colour of the visible spectrum
did Isaac Newton allegedly invent to make it 7?

Q: Which colour of the visible spectrum did Isaac Newton allegedly invent to make it 7?

Indigo.. Newton wanted the rainbow to have 7 colours to match musical notes. Indigo is barely distinguishable from blue and violet. Marketing before there was marketing.

Question

Accepted Answer

Indigo. — Newton wanted the rainbow to have 7 colours to match musical notes. Indigo is barely distinguishable from blue and violet. Marketing before there was marketing.