Due to its bright and cheerful appearance, the Orange paint is definitely an eye-catcher in the battlefield, making it one of the most unlikely option when it comes to picking a camouflage for your tank.
In fact, the practicality of this paint has often been called into question since most players would agree that painting a tank orange in real life is definitely an invitation to a disaster, which mainly involve getting that particular tank destroyed. However, since the release of the Iran map, the orange color might have a use as a camouflage after all. It's not ideal; more of a so-so camouflage and it sometimes doesn't work. Though honestly, it can be considered a good paint if you want to hide the drugs you are using on your tank.
That said, most players (and there are quite a lot of them) tend to pick orange as the paint of choice for their tanks not for the purpose of camouflage - surprise, surprise! (not really) - but the paint is mainly used as a very bold statement to other players... A statement which affirms that they are good enough at playing Tanki X to the point where their tank could even have been painted bright yellow and still they could destroy your tank before you could do the same to them.