Iron rusts from disuse, stagnant water loses its purity, and in cold weather becomes frozen; even so does inaction sap the vigors of the mind. - Leonardo da Vinci

But leaves of yellowish green do not, when they reflect the atmosphere, create a reflection which verges on blue; for every object when seen in a mirror takes part in the color of this mirror; therefore the blue of the atmosphere reflected in the yellow of the leaf appears green, because blue and yellow mixed together form the most brilliant green, and therefore luster on light leaves which are yellowish in color will be a greenish yellow.

If there's no love, what then?

The atmosphere is blue by reason of the darkness above it because black and white make blue.