In reference to "Compass Ghost" paint. The blue on the F-15 was only part of a camouflage scheme. The other part was a camera a light projector. It was tested on an F-4 at Eglin AFB in the early 70's. The camera was mounted just behind the cockpit and lights were under the nose and outer wings. The idea was to the shade and intensity of the projected light to match the sky color behind the aircraft. The idea didn't work and project was cancelled. The F-15 paint was already in the contract, the AF kept it. I was stationed at Eglin AFB when the test was done.