Which of these passages includes an example of an analogy?

1. The sun set amid the paper-thin clouds that slowly changed colors from bright pinks and greens to purple. Finally, everything faded to gray as the sun vanished behind the hills.
2. The walls were covered in blue paint that was the same color as the sky on a cloudless day.
3. I chose way too challenging a slope for a beginning skier. I was like Wile E. Coyote running off the edge of a cliff, hovering in thin air, and then plummeting to the ground.
4. The piano wheezed like an old horse. Enjoying the noise, the two children banged on the keys even harder and drowned out their parents' cries for them to stop.