I build some drawers for under the seats of my 2018 Rpod #178 HRE and needed to stain them. Reviewing the other posts where a candidate Sherwin William stain was posted. Checking with S.W, the base Charcoal has been discontinued. S.W. has a new Carbon base which might be close to Charcoal. But S.W. wanted some $ for their matching service and I did not feel confident with the staff. What I also found is that stain matching is not an exact science. It depends on the kind of stain, the wood being stained, the amount of wood grain, and the number of applications/coats which affect the density of stain color.
When trying find something to match to, I found that the Rpod has a number of things to evaluate. The kitchen drawers and trim moulding are different from the flat panels in the kitchen and seating areas. I also suspect the panelling is not real wood as the wood grain is stained black. When I stain birch veneer, the grain does not absorb stain and become a light color. And, pine kitchen drawers seem to have a bit more gray in the color than the panelling. Net, net, you gotta pick what looks best to you. I picked custom stain formula closer to the panelling as my drawers are under the Rpod seats.
The drawers I made used 1/2" x 2' x 4' birch plywood project boards from Home Depot. Here is my pretzel logic and alchemy of matching stain. Reviewing the S.W. stain formula posted on this forum, it starts with a Charcoal base and adds white which I evaluated to become gray. Then, other colourants added are Deep Gold and Maroon which I evaluate to be a brown.
I used Minwax Penetrating Stains (Walmart $5/can). Starting with Classic Gray #271, I had a half a dozen failures using Fruitwood. I found adding Minwax Stain Dark Walnut #2716 gave me a pretty good result. I used a plastic spoon, as in picnic cutlery, and put 3 spoons of Classic Gray and 1 spoon of Dark Walnut in a plastic cup and stirred. I used a folded paper towel to apply to my birch plywood. I did two applications of stain with 10 minutes of dry time between applications. After dry, I sprayed a Rustoleum clear gloss to give a nice finish and a bit of hardness to the surface for durability.
Depending on color goals, you can adjust more or less grey relative to the Dark Walnut. And, going lighter or heavier on the second application of stain will change the density of the color.
Here are some pics of a test board in front of the kitchen cabinets and the finished drawers.