The Orielly's near me does paint mixes based on my paint code. They make rattle cans, and quarts that I'm aware of. If you have a common color it's cheaper and on the shelf. They have the paint pens though I'm not sure if they mix those.
I've been very happy with the color matching over three vehicles. My 14 JK Copperhead Pearl (may it rest in peace) rattle can was perfect.