During the 1966 Vietnam War deployment of the USS Kitty Hawk (CVA 63), a number of aircraft in the air wing were given camouflage paint jobs on upper surfaces that would normally be gull gray. I believe I've posted at least one previous example.
Here's another: A North American RA-5C Vigilante recon aircraft of RVAH-13 on the deck of the Kitty Hawk. Hard to see, yes?