Question: Do all the colours of the spectrum travel at the same speed?

Sam Horrell answered on 17 Jun 2013:

The speed of light is a universal constant so is always the same speed. The change in colour that happens in the visible light spectrum is a result of the light being a different wavelength. If you look at the electromagnetic spectrum you can see that visible light begins at around 400 nanometers (violet) and ends around 700 nm (red).