Having been to the Regensburg plant, every time the paint booth (there were only two) changed colors it required a technician to change the applicator tips on the robot & he had to purge the system and lines to ensure nothing remained of the previous color.....so.....
I estimate the whole process took about 45 mins...so that's 90 additional minutes of labor & a few more Euro in plastic parts. Even with all that it's still very profitible
My personal favorite was Arctic Metallic. Sometimes blue, sometimes gray, sometimes greenish.