After many successful launches with the Delta II, ULA made the Delta IV rocket orange. What's the reason for this strange color change?
Also the Atlas V's first stage is orange, is there any specific reason that launch providers like coloring their rockets a specific color?
After all, it seems expensive to paint a whole rocket which will be discarded after a single launch. If the bright color is for tracking the rockets, why not use a paint scheme like the Saturn rockets had?
This picture shows the Delta rocket evolution, and shows the Delta IV in blue. What's with the sudden color change?