Go by the paint code for the year your truck is.
As you see with the non-year of your truck the code is not the same and the color is a little off.
Car / truck manf. will change the color a little and that is why the different code.
As for the color names being different with the same codes different paint manf. called them by different names for the same code / year and why you are seeing the different name & same code for your color.
If painting the whole truck then you don't need to worry on color matching as it will all match when painted.
If you are only painting panels and not the whole truck then you would want to keep the 2 panels not next to each other. Like fender to hood are not really next to each other to see the difference but the fender to door you would.
Also note on medal flake colors you can change the color a little by the air psi used to spray with.
Lower psi darker the color, higher the psi the lighter the color.
On either metal flake or solid colors just painting in a different manf. than what the paint on the truck was done in can be a little off too. Factory don't in say RM and you use Dizzler then add in the air PSI and you have the making for fun!
BTW our trucks were painted in single stage - read no clear coat!
I would say let the shop do what they do day in and day out - fix & paint!
You can ask them if there is anything you can do to help but I would say other wise let them be.
Just my .02
Dave ----