Excluding dwarf planets, such as Pluto which are trans-neptunian objects obviously further away from the sun, so due to inverse square law less area of light and therefore less heat, of course things such as albedo matter here. But considering the principle, a simple question arised in my mind, which is colder Uranus or Neptune? According to this principle, Neptune should be colder, which is true, But other sources state Uranus. According to my analysis, I think that the first one, Neptune holds the record for the average coldest temperature, whereas the later, Uranus has the coldest temperature of a planet (In our solar system, excluding exoplanets such as rogue planets, etc..). Stating that:

Uranus holds the record for the coldest temperature ever measured in the Solar System: a very chilly -224℃. The temperature on Neptune is still very cold, of course – usually around -214℃ – but Uranus beats that.

So why is this? Ideally Neptune should have the lowest mean temperature as well as the lowest temperature recording (according to present data), why is this, Any reasons?