Someone a while back said a company (maybe Danaher) paints the inside of their sockets and people here have believed this nonsense ever since. Here it is repeated again. I'd be willing to bet NO company paints the insides of their sockets silver. That matte gray finish is chrome! Snap On chromes the inside of their sockets. So does SK. No paint.
http://www.garagejournal.com/forum/showpost.php?p=4993078&postcount=139
This.how could you only chrome the outside when its a dip process?
This is chrome loss and flaking plating, not paint. The chunk of stuff is nickel and chrome on probably polishing debris.
Chrome does not cover surface imperfections. It exaggerates them. Almost all tools are first plated with some softer base metal. Some advertise their finish as "nickel chrome". But it's two seperate platings.
The base plating is highly polished prior to chroming. The insides of the sockets, can't be polished, so any little surface defects in the tool steel, will be exaggerated by the chrome on the interior. This is not necessarily cause for concern. But this is why you see shiny at the top, then the dull surface inside. And because it's not an easy surface to clean, the plating may be a bit spotchy*.
The best stuff you can use to clean and chrome is all toxic carcinogenic ****. Cut the US manufacturers a little slack. They have to comply with federal environmental regs China and Taiwan don't have. But if you buy new tools with chrome missing from the exterior, send them back. If you get the same problems back again, switch brands.