Pawel, that’s my guess as well. They could get color changes for different environments but it’s probably not the same as paint. But what do I know, that’s why I asked the question. The first person to suggest it in a meeting of the brass probably got the same response I got. 
Sory to butt in, but on the faded paint subject. I just sprayed up a mig with a camo scheme and thought it looked like id coloured it in with kids felt tips. I tried flory models pro modler grey wash, and it toned it all down and gave a nice faded feeling to the colours. It mskes a nice filter, and being a water based clay wash its easy to remove too if you put too much on.
Hello!
You can get a colour-changing paint nowadays - the technology is there. There’s just the question of cost. Remember those cars that changed colour when dipped in hot water? Or the magic cups that showed a picture when a drink was poured in? Thera are also coatings that change colour when electric field is applied, too - but would they be practical to buy and maintain? At the end of WWII USAF got rid of camouflage after doing some math and after it showed that it cost more than it’s worth.
Have a nice day
Paweł
Yes, in Egypt, around the time of 2nd Alamein in Fall 1942, the 8th Army had adopted a pinkish sand shade that was supposed to be standard on all tanks throughout the 8th Army- with or without a disruprive pattern on it. Prior to that camouflage had been an individual unit level choice with units adopting theit own patterns and colors, and as such could be more easily identified on sight by Axis intelligence folks.
And of course in the post WWII Middle East in Oman, there were the famous “Pink Panther” Landrovers of the SAS during the late 1950’s/early 1960s.
The USAAF used a pink Sand Shade that was nicknamed “Tittie Pink” for use in the MTO. And a very similar color has been seen in the 1st Gulf War on RAF and Italian AF aircraft
There was actually some experimentation done with this for aircraft tasked with daytime ASW work in the Atlantic. It was found that during daylight, lights of a certain brightness along the leading edges of the aircraft could delay visual detection under clear sky or mostly sunny condtions by essentially removing the shadow shillhouette from the brighter background sky until the aircraft was much closer to its’ target. This was also one of the reasonings behind the Dark Gull Gray over White adopted for ASW work in that theater in WWII.
There were several programs to add lights to jet intakes. The jet intake looks very black against skylight, an actual source of light. However, it generally was not worth the trouble. By the time people began to work on the visibility problem seriously, small compact battlefield radars and SAMs were reducing the threat from eye pointed gunfire. While optical stealth has to be kept in mind, folks believed radar stealh was more important.