From the United Nations Information Centre:
How are you celebrating World Oceans Day today? In New York City, the iconic Empire State Building will be lit in white, blue and purple, representing the different layers of the ocean. White at the top represents the shallowest, sunlit waters and also the polar ice cap. The blue represents the slightly deeper ocean waters, and the purple even deeper waters in the ocean. The unlit portions, or black, represent those parts of the ocean where the sun does not reach.
We’ll try to track down a picture of the Empire State Building. In the meantime, enjoy this view of the Pacific taken in Olympic National Park.