I'm green at the start. Halfway through I'm mostly red with dark freckles. By the end, I'm often smiles of green, white, then red.

The sky's deep growl without a beast, followed by a dazzling feast. I'm slower than the light, hearing me will give you quite a fright.

I paint the fields in scarlet hue, my seeds top bread and bagels too. Yet from my sap strange dreams may creep, what flower gently lulls to sleep?

Invisible rain from your skin, a natural shower when heat's your kin; the gym's symphony when effort's in play, or when nerves dance in a stressful ballet.

It's been around for millions of years, but it's no more than a month old. What is it?