You've kind of ruined the moment a bit now. The obvious answer is, blue.

Bare in mind, this is supposed to be a quick fire, face to face questioning not a philosophical debate🙄😂.

The next quickfire question is.......

What do cows drink🤔. Milk, is often the answer, but is obviously wrong. It's water.

Grass: Green

Sky: Blue

Ciws: Milk