On the U.S. side of the pond, this will get you close:
https://www.summitracing.com/parts/shw-bsp303/overview/You'll need a platinum or white base coat. You may want to try both to see which is best, assuming you have a non-faded sample. Of course, the number of coats will have a noticeable effect on color shade. I have used an airbrush to spray samples on a piece of sheet metal so I could test various combinations without wasting as much paint as a regular gun takes. If you are looking for a Concours-perfect OEM match, you'll need a non-faded sample and may need to try a variety of brands and different candy reds, base coats, etc. There are others on this forum that have put a lot of effort into getting a perfect match, maybe one of them will add something to this thread.
The 1 quart ready to spray should be enough for the bike with a little left over.
You'll need a good respirator, etc.
Both Summit Racing and Eastwood carry a wide variety of types/brands of candy apple red, including powder coat. Of course, there is always your local automotive paint supplier that will have a lot of paint samples. I might try a candy powder coat on something one of these days just for fun.
