VEX Parts Legal to paint/colour

I was wondering what VEX parts are legal to paint/colour. I know that we can paint the metal and gears, but what about wheels, motors, motor controllers, wires, Joysticks, Cortex, and all of that other stuff?

I’m pretty sure anything can. I don’t think I’d recommend any paint on electronics though.

Within the Vex rules, be sure that the sensors are not using the new color functionally. This is supposed to be non-functional decoration.

So look at R15.a as it pretty much covers sensors, motors, controllers not being altered in any way. Paint would seem to be an alteration of these components. So it may be deemed illegal. The debate is whether paint alters their state beyond decoration (besides the weight of the paint making the component a few milligrams heavier). Stickers and labels are deemed OK. Writing in magic marker is OK to label the part. So why not a coat of cool paint on top to make it wicked cool?

But if you were ignoring all this and forging ahead anyway for fun…

Painting plastic can be very tough. Most paint placed on the plastic parts - like a joystick - has a hard time staying on the plastic for long without flaking off. Sanding and chemicals are typically used to ensure the paint adheres to the plastic.

You will spend a much of time taking things apart, sanding/treating and then painting the parts. Getting good with spray painting makes for a clean finish and no globs or runs. Spray painting takes practice.

This site had some useful tips.


  1. As an alternative to sandpaper you can purchase a product called liquid sander. Home Depot carries one called Klean-Strip. It cleans and removed shiny surfaces at the same time, helping to create a suitable surface for new paint. This product can be used indoors. There’s also one called Krud Kutter Prepaint Cleaner which cleans the surface and can be painted over after just ten minutes
  2. Use paints that are specifically formulated to adhere to plastics. There are several available on the market such as Krylon Fusion for Plastic®, Valspar® Plastic Spray Paint, and Rust-Oleum Specialty Paint For Plastic Spray.
  3. If using regular spray paint then your item will need to be primed. Use a specially formulated primer such as Rust-Oleum Specialty Plastic Primer Spray or Krylon Indoor/Outdoor Plastic Primer.

PPG has some handy list of how to paint plastic car parts. (page 2-1)

We are allowed to use non-Vex materials as color filters for the light sensors as long as that is their only functionality. The color of the sensor itself doesn’t affect its behavior, regardless of sensor type (just don’t paint over the important parts).

Official ruling link:

Paint away!