Beijing's "Water Cube" is illuminated.

Beijing's "Water Cube" offers a sign of the times with illuminated numbers.

Normally a water-like blue, The National Aquatics Center, also known as the 'Water Cube,' brightens the night sky with color on March 31, the same day the Olympic torch is welcomed to Beijing at Tian'anmen Square.

(Photo credit: Gong Wenbao/China Photo Press)