the slippery "F" word - my solution

[LastPoet]

The sky is not blue, we percieve the sky being blue because that is the highest wave frequency we can see. Other animals see it as being red or ultraviolent.

Solja, the sky is 'blue', 'blue' is the name we humans have come up with to designate that color, that corresponds to that wavelenght. And other animals do not see it 'red' or 'ultraviolet', they can or can't see the wavelenght and can or cannot perceive differences between them (depends on the animal). But I doubt they conceptualize it in words.

ultraviolent

Hehe, atheist joke: that's what theists see in the sky, its the home of their ultraviolent sky daddy that, if you don't worship him, you're fried.