: if colour is a spectrum going red thru purple then why do we have colours like magenta or pink, which seemingly connect purple back to red?

Question

: if colour is a spectrum going red thru purple then why do we have colours like magenta or pink, which seemingly connect purple back to red?

In: Physics

Answer 1

There’s a difference between the possible colors that a single wavelength of light can produce (monochromatic light), and the possible colors that we can see.

You can mix “pure” colors of single wavelengths to make a new color that your eyes can see.

The single-wavelength colors make up the spectrum you described. The other colors are a mix.

The image below shows the colors we can see. The line around the outside is made up of the “pure” monochromatic colors. Draw a line connecting two of those colors to see what they can create when mixing.

https://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/PlanckianLocus.png/1280px-PlanckianLocus.png

Edit: Purple doesn’t connect back to red. The color wheel is a lie.