Why paint never matches by eye
Hold a repainted fender up against the door beside it and the difference is rarely the color name on the paperwork. Metallic flake lies down differently on a panel sprayed flat than on one hanging on the car, and years of sun fade the old paint until the factory code describes a color your vehicle no longer is. A match has to be built for the car in front of you.
That is why a poor repaint shows in daylight and hides under shop lights. The eye catches a shift in lightness or sparkle long before it can name a color. Trucks make it harder, with big flat panels that give a mismatch nowhere to hide. Computerized color matching exists to take the guesswork out of that first step.
