The Russian Air Force has decided to go back to pattern type camouflage paint jobs on its combat aircraft. The recently resigned defense minister had ordered all combat aircraft to be painted one of several shades of gray. This saved money because the aircraft did not have to be repainted to a different camouflage pattern if it was transferred to another part of the country. The new defense minister still wants to save money but he also wants to cheer up the combat commanders and pilots who want their camo patterns back. So aircraft won’t be repainted until they go in for repairs of extended maintenance. Thus it may be a few years before all aircraft shift back to camouflage patterns. It was not revealed what those patterns might be, indicating they have not been selected yet.
Military aircraft have, like ground troops, long used camouflage to make them more difficult to spot. Sometimes the camouflage is very minimalist. For example, during World War II radar-equipped night fighters were painted black to make it more difficult for bomber crews (the usual prey) from spotting the night fighter soon enough to shoot it down. By the 1980s, the first stealth bomber (the F-117) was also painted black. While the F-117 was largely invisible to radar, it could be seen with the naked eye. Thus it operated mostly at night and was painted black like the older night fighters, for the same reason.
Air forces use camouflage patterns for two reasons. First, is to make it more difficult for enemy aircraft above, or enemy troops below, from quickly locating the aircraft. For that reason aircraft have two different camouflage patterns. On top of the aircraft is a pattern that makes the aircraft blend in with the ground below (when viewed by an enemy pilot above). On the bottom of the aircraft is no pattern at all but rather a bland monochrome that makes the aircraft harder to pick out from below. The U.S. Air Force has four "looking down" patterns, for different types of terrain. There's even one for the arctic (white, gray, and black). The second use of the patterns is to make it easier to pick out your own sides aircraft. The camouflage doesn't make you invisible, just harder to spot in a hurry. The most recent development is the "digital" patterns found on the infantry and their vehicles, to make aircraft more difficult to spot against vegetation.
Not all special paint jobs were to make the aircraft harder to see. During the Cold War some aircraft that specialized in delivering nuclear weapons were painted white, a color that would reflect some of the heat energy from a nuclear weapon going off nearby.