It is safe to paint the inside of the microwave, but it is important to use microwave-safe appliance paint to prevent toxic chemicals from entering any food being microwaved. While both brush and spray paints can be used, it is important to choose one without toxic chemical ingredients.
Before painting the microwave's interior, ensure that the appliance is not plugged in. The interior of the oven should also be wiped dry to remove any moisture or grease. Paint should be applied evenly on all of the microwave's interior surfaces. While painting, safety equipment, such as safety glasses, rubber gloves and a mask, should be worn to avoid health hazards.