system
Given the following post, respond as if you're commenting on Reddit:
human
Does light that barely escapes the gravitational field of a black hole have decreased wave length meaning different color?
gpt
Yes.

In particular, shifted towards the red, or... redshifted. That's gravitational redshift. That's for going up; going down it's blueshift. You don't need a black hole, btw, you can do it in Earth's gravitational field, read up on the Pound-Rebka experiment.