We recently attempted to create magnets for a customer with a silver truck.  The goal was to put his silver color on the background of the magnet so they wouldn't stick out like a sore thumb.  Little did I know this color match would be an impossible one. We pulled every trick out of the hat to get the best match.  We used our spectrophotometer to get LAB values, but when we printed the results, the color printed wasn't close to the color of his truck.  We also tried to match the color using a Pantone swatch to try to get close, but even that failed miserably.  The silver on the magnet would either be too light or too dark...never dead on. We learned the hard way that you can't perfectly match the color on a vehicle.  And here is the reason.  Vehicle paints have a couple things going on that complicate the matching.   First off, it has a clear coat on the surface, and that can distort the color of the pigment.  Trying to get a reading with a measuring device  (like our spectrophotometer) wouldn't work due to the clear coat contaminating the true color.  I would compare it to trying to look out of dirty glasses...the view is distorted. The other very big reason why car paint can't be printed is the metallic features in some vehicle paints.  Funny how we didn't notice this when trying so hard to get a match, but the color will shift when you look at it at different angles.  Strait on, it's a light silver...look at the surface at an angle, the color turns darker.  That is the metallic features in the paint. To overcome this, and get the best result for our customer...we compromised the silver color of the magnet, and made it a very light silver.  This way when you look at it straight on...the color was pretty close.