Panel paint

I've noticed on most Clio sports the paint seems to be slightly different shades on the wings and doors?
It appears on most/ all colours where the wings look the same but the doors are slightly different - has anyone else noticed?
I know plastics when painted show different to metal panels which would explain the front wings, bumpers but are the rear wings plastic?
 
Same on most cars, pearl is usually best for matching plastics due to the paint process.
 
Wings + bumpers are sprayed seperate to the main car body, and arent blended in the factory............thus its never spot on.
 
Except for the pearl colours but that will change on the Mk4