Don't quote me on this, but I have heard they are not allowed to stop the production line, so the worker on the line basically has to install what is provided to him and the issue needs to get addressed later. The worker obviously knows the color didn't match, but that was the part erroneously provided to him by somebody who did not have the truck sitting in front of them. Since things are falling through the cracks, they probably need to revisit the process.
Could be. Most often though the parts are picked ahead of time for each vehicle as it moves down the line and each station has only the parts it needs. Not to say someone didn't grab the wrong part though. Regardless, Ford needs to work on their QC. It's bad enough when guys have to wait months and months and watch guys get their trucks that placed ordered way later than they did let alone have to go back to the dealer to get crap fixed or wait for the dealer to fix it if they catch it.