The photos below teach a painful lesson. The person who rebuilt this salvage VW Rabbit missed the metallic flake "flip flop", didn't blend the color through the doors and the panel gaps?? Well.....I'll let you be the judge, jury and executioner.
Folks this is why you bring your local paint store a damaged panel and not the generic paint code. Your paint store will bring the damaged part into the sunlight (They will also use a Sun Gun) and then match their paint chip variations to the factory color so this kind of miss match never happens.
When in doubt? Blend, Blend Blend. Unless the car is white or black attempting to Butt Match can be risky. What is a Butt Match? When you attempt to match a new freshly painted panel to the adjacent's original paint without blending. (If my explanation is not clear take a look at the attached photos :)
If the color is a metallic don't cheap out when it comes to paint. Why? The less expensive alternatives have a larger flake that makes it difficult to Blend / Flop into the factory OEM finish.
What is FLOP? How often have you driven next to a gold or silver car and watched some panels "flop" lighter or darker while others remained the same? Often times you can even pick out the blend in a panel based on the flop not being correct. The flop is caused by the orientation of the flake in the pigment, the edge of the flake is the darker side, while the face is the more reflective side. The orientation of the flake can be manipulated through spraying technique, air pressure, and humidity. The flop can be visually be seen when using three different standard light sources for viewing condtions. CWF (Cool White Flurescent) (Horizon) and DAYLIGHT. The base pigments in a coating reflect light back to your eye. As the coating goes translucent, the actual polymers in the coating refract the light waves going back to your eye. AS THE LIGHTING changes, you see different colors.