Thoughts of a Golden Afternoon

The sun is shining yellow and the sky is glowing blue,
But I can’t decide which is happier,
Can you?

Yellow is for smiles and all things fun!
Blue is for Sorrow and when you’re feeling glum.

But when the sum is hiding,
It seems oh so sad,
Like a little child who knows he’s been bad.

And the sky is always laughing,
Like a big, blue clown.
When in its azure coat,
It hardly ever seems down.

So, I wonder, is the sky to blame for this colour contradiction?
Or are these just examples of stereotypical fiction?