My teacher asked me once
'What's the colour of the sky? '
I replied 'It's blue'.
She then started to explain how that was wrong.
Not in the literal view, because what we do see it's the blue colour when we look up.
She taught us how it was an effect,
a mixture of rays, lights and colours that would blend in the infinite sky.
She spoke of waves and the atmosphere and the sun.
That sounded so intelligent, it sounded so right.