You can do this in the prologue by ising the paint studio.
But if you don't do it there. You need to uograde your garage to level 30 (a fully leveled toolbox) and then use the pain studio to paint the car.
Save time and do Like new at the sane time.
Using Sandbox is the quickest way to get both if you miss it in the prologue and want it fast.
Send the car to the paint shop and then press
to restore it to factory by then pressing
.