Here's a way to think about it:
* Sunlight Intensity: The intensity of sunlight decreases with the square of the distance from the sun.
* Earth's Sunlight: Earth receives about 1367 watts of sunlight per square meter.
* Uranus's Distance: Uranus is about 19 times further from the sun than Earth.
* Uranus's Sunlight: This means Uranus receives about 1/361 (19 squared) the amount of sunlight Earth does, or about 3.78 watts per square meter.
To put it in perspective:
* The amount of sunlight on Uranus is about equivalent to a cloudy day on Earth.
* It is so faint that a human wouldn't be able to see anything in color.
Interestingly, Uranus's atmosphere reflects a lot of the sunlight it receives, making it appear quite bright to telescopes despite the low light levels.
