VANDENBERG AIR FORCE BASE, Calif. — The final launch of the venerable Delta II rocket has left the world a little less blue. That is not to say that the rocket's retirement has not been met with ...

The blue Moscow guppies have a metallic sheen and electric blue color while the blue-variegated delta guppies have orange-red fins, blue and orange patches, and gradient blue scales on their sides.

Adiantum raddianm or variegated delta maidenhair fern photographed in the Conservatory at the New Orleans Botanical Garden in City Park in 2010. Writer: [] (The Times-Picayune/NOLA.com ...