ajmooch

Have you taken a look at any of the machine-learning driven automatic colorization tools out there, such as this? I'd be curious to get a professional's opinion on the automatic results.

In a vacuum, the entire spectrum ("every color") travels at the same speed, but when passing through a medium, the speed with which the waves propagate is dependent on frequency (among other things), so the different colors do travel at different speeds. See: dispersion and phase velocity.