* Hydrogen (H2): About 83%

* Helium (He): About 15%

* Methane (CH4): About 2%

This methane is what gives Uranus its distinctive blue-green color, as it absorbs red light.

There are also traces of other gases, including:

* Water (H2O): Found in the deeper layers of the atmosphere

* Ammonia (NH3): Found in the upper layers of the atmosphere

* Hydrogen sulfide (H2S): Found in the deeper layers of the atmosphere

* Trace amounts of hydrocarbons: Like ethane (C2H6) and acetylene (C2H2)

It's important to note that Uranus's atmosphere is layered. The upper layers are very cold and consist mostly of hydrogen and helium. As you go deeper, the temperature and pressure increase, and the composition becomes more diverse with the addition of heavier elements.