Auto Vehicle Color by Line

Every vehicle on a line is painted in the color of its line: buses, trucks, trams, trains with all their wagons, ships and planes. Change the color of a line and its vehicles follow. Vehicles that join a line get its color too. Works in the background, no tool needed. Vehicles without a line keep their color. Some vehicle models cannot be colored at all (the color button in their window is grayed out), those stay as they are. Existing savegames: the vehicles are painted step by step (50 vehicles per second, so the game does not stutter). With many vehicles it takes a moment until all of them have their line color, e.g. about 10 seconds for 500 vehicles.