How do brake tail lights change the color of the light you see?

Question

How do they change the light you see from white to red?

Answer 1

the lenses are colored.

colored lenses only allow certain wavelengths of light through them.

In the case a brake lights the red lenses only allow the red portion of the light bulbs light through.

Hope this makes sense!

Answer 2

The lens that the light passes through (the tail light lens) absorbs all light except red which passes unaffected.  So all other colors are blocked except red.

Answer 3

The white light that the lamp gives off contains all the colours of the spectrum:-

  Red, orange, yellow, green, blue, violet.

You could say that of these colours, the red lens lets through the red light only (so we see red), and the other colours are absorbed by the red lens.( they don't get through the lens )

In reality, the red lens also lets through a little of the other colours as well, but it lets through much more red  than any other colour.