See if you can bet a sample from someplace that sells it, or check with a local paint store or 2 to see if they have it in their system.

You might be happy with SW Iron Ore, if it does not have to be an exact match. If you have a sample take it to the store and their machine will match the color.

Just so you know - SW gave us their James Hardie Iron Grey "match" from their system and it is not the same - SW looks more blue undertones.

Sherwin Williams "SW 7062 Rock Bottom" is a very close match. It's only 0.1% darker if you stare at both side by side.

@Huzkit Glad it helped. Thanks for doing the homework and saving us time ordering experimental paint. From what I can see, you're better off going with Rock Bottom because the difference is so trivial it won't matter once the job is done. I'll still love the tone with the 1% variance once past the research stage.

If you're still looking for perfection, another one to consider is:

https://www.myperfectcolor.com/paint/347713-james-hardie-jh90-30-iron-gray

They claim to match it 100% because they have the original sample and also have a satisfaction guarantee policy. They use the Benjamin Moore brand and allow you to order quarts if you want to test first.

I'm curious what level of sheen you are after for your siding. glossy paint doesn't hold stain as much but amplifies imperfections and hide the natural color tones. I'm thinking between flat and eggshell.

My comparison of the JW Iron Gray vs Sherwin Williams SW 7062 Rock Bottom:

@Huzkit I would love to see photos of how your project turned out and if you were happy with the outcome!

Turned out perfect ! love it.

Look at Ben Moore Nightfall just saw video of house that had Hardie iron gray and sprayed 2 nd coat on trim to match ( really close to iron ore too.

Can you all confirm what sheen / type of exterior pant you used to match the Hardi board?