You probably spotted many people wearing green on Monday in honor of St. Patrick’s Day, but green is a popular color all year round because it tends to spark positive emotions.

Today, the world's oceans appear deep blue, contrasting with the light blue color of the sky ... which would have made Earth look green from a distance. Over the green-ocean period, the ...

The green-tinged Comet Nishimura is zipping past Earth, and you have a few days to ... vaporizing its ice — is a "pleasing blue-green color," King added. Read next ...

One of the best things about earth tones—and perhaps another aspect of their popularity—is that they're incredibly easy to ...