Normally, when you want to change the paint color on your car, you're facing lots of disassembly, extensive prep work, and expensive time in a spray booth followed by seemingly endless hand blocking. Instead of the conventional method, a new technology might be on the way to make a color change as easy as twisting a knob. It's actually quite similar to the magic General Motors
has wrought with their magnetorheological dampers. The variable-color paint works this way: prior to paint, the body gets a special polymer coating that's got paramagnetic iron oxide particles in it. When a current passes through this coating, the ferrous particles change their alignment, which alters the way they reflect light, effectively changing the car's color. The default color when the car's not running is white, which hints at a future of exceptionally bland parking lots if this technology takes off.
[Source: Motor Authority]