You can change basic information on your vehicle registration—including the color of your vehicle—by contacting your local Department of Motor Vehicles (DMV). Notifying your DMV should be enough to have the color change instated on your registration.
Not every state requires you to update your registration following a paint job, but it’s a good idea to check anyways. Laws can vary from state to state, and depending on where you live, there may even be local ordinances that prohibit certain paint colors for cars.
Remember to notify your car insurance company as well—modifications may impact your monthly rates.
If you’re worried about increased rates, you can always check with your insurance agent before making any modifications to your car.