Newslink: Delta Blue: Last Delta II Rocket Launch Leaves Behind Colorful Legacy

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 hasn't been met with a tinge of sadness. No, it was not a matter of sentimentality. Rather, it is one of hue.

https://www.space.com/41851-last-delta-ii-rocket-launch-blue-color-explained.html