Norton commando 850 mk 3

Candy apple red i believe

Candy Apple red over a silver base coat

Phillip, there was an article in "Roadholder" noc mag ,probably a year ago. with modern equivalent options.l was more interested in older twins, probably 20m3S etc.was also covered.

If you want a lighter candy apple red, then paint it over a silver base coat, but if you want it to be darker paint it over a gold base coat. The old candy apple red could turn yellow in ultra violet light or sunlight, as it happened to one of my bikes. The paint that is being used today, has got over this problem 

Although many here will know, it might be useful to explain that a candy paint finish is a coloured, transparent lacquer over a silver metallic (or gold etc.) base coat. This requires a skilled painter to apply the lacquer coat uniformly because the colour will be darker where it's thicker.

Most paint finishes these days are a clear lacquer over a coloured base coat - even I can do that.

A candy finish really stands out over a base/clear paint job so well worth doing if it's done well but there are lots of Candy Apple Reds out there, e.g. https://alchetron.com/Candy-apple-red-(color)
You need a find a custom paint shop and take the original tank in for them to match.

There is such a paint shop near me and I've been meaning to check them out:
https://www.facebook.com/MaskMonkeyCustomPainting/
I'll report back.

A few years ago I had my Mk2A painted by Faircharm restorations in Leicester (recommended by someone on this site at the time). The guy did work for Mick Hemmings I believe and said he matched mine to an original sample of the paint supplied by Mick. The work wasn't cheap but it was outstanding. A quick look on the net and he seems to be still in business.

I like to deliver and collect for peace of mind.  I am aware of Faircharm but we also
have Dream Machine in the East Midlands.  Both well regarded businesses.