Newton and the Imaginary Colour

I was thinking about colours today – specifically which colours correspond to which wavelengths. The results are a bit weird:

• Red: 750 – 620 nm
• Orange: 620 – 590 nm
• Yellow: 590 – 570 nm
• Green: 570  -495 nm
• Blue: 495 – 450 nm
• Violet: 450  -380 nm

Here I’ve used the figures given by Wikipedia (sourced from catchily titled the