You don't want to paint the tread of the wheel that touches the rail or it will affect electrical pickup. But the front and rear faces of the wheels can be painted without any affect on electrical pickup. Chris Toth
Look to see if there are electrical "wipers" that touch the inside of the wheels. Some engines have these and some have spring loaded rods that pickup current from the tire to the motor. If your engine has either of these, DO NOT paint the inside of your wheels or you will have a "dead" engine also.
all my engines are Athearn 4 axles. Everyone of them have been painted only on the outside face. You can't see the inside face because of the "traction Motors". just that on the outter "lip" of the wheel face, the paint will come off after a couple minutes of running, but it doesn't affect operation.
