I had my inner matched in that color. No, you can't buy the paint anywhere, so it does need to be a mixed match.
Gunslingers Custom Paint, in Golden, Colorado. Lots of people send them parts to be painted. You could do the same, and include one of your stock lids, for the color match.
They'll shoot the color and compare, until they get it right.
Consider this as well, they paint some of the CVO bikes, and some of the sets for the sheet metal program HD has...I was so pleased with their work on my 10 FLHXSE Teq Sunrise, I brought them all the tins from my 2003 Heritage Springer Softail. HD has never released the silver paint from the 100th anny bikes, but Gunslingers can still mix and match until it's perfect.
Oh, and I paid $425 for the painted inner, and they polished both my side covers. I had dull spots in the clearcoat from my wife's chaps.