system
Given the following post, respond as if you're commenting on Reddit:
human
Why is Jupiter a different colour to Neptune and Uranus?

Since they are all made up mostly of Hydrogen and Helium?
gpt
Although mostly hydrogen and helium, the atmospheres of Neptune and Uranus contain higher levels of methane than Jupiter.  Methane absorbs strongly in the red and into the infrared region of the spectrum, this in turn gives Neptune and Uranus their bluer colours.