Theentireplanet isn’t blue, of course. The clouds themselves are white, reflecting the white, direct sunlight back out at any onlookers. Ice — such as the caps on our planet’s poles — appears white for the same reasons. The continents, similarly, appear either brown or green from a great distance, depending on the seasons and how covered-in-plants the terrain isThis teaches us something important: the Earth isn’t blue because the sky/atmosphere is blue. If that was the case, all the light reflecting off of the surface would be blue-hued, and we simply don’t see that. But there’s a hint that comes from the truly blue parts: Earth’s seas and oceans. Theshadeof blue that the Earth’s water appears varies based on how deep the water is. You’ll notice, if you look closely at a photo like the one below, that the watery regions borderingthe continents (along the continental shelves) is a lighter, more cyan shade of blue than the deep, dark depths of the ocean.