The wall is almost certainly already some variation of Swiss coffee, which is like a drop of black and two drops of umber per gallon… juuuuust enough to give it a little color.
When I used to help people pick colors the primary advice I gave them was that once it’s on the wall you will never see the difference between the four shades of [color] you’re looking at because at scale your brain blends it in with the lighting and ambient color of the rest of the room.
Sheen makes more of a difference, and the answer is always satin/eggshell for living spaces and gloss for kitchens and bathrooms (because it’s more moisture resistant and washable). Flat can go fuck itself, it only exists as a cheap option for track homes who don’t care about your paint looking good for more than six months.
Source: worked at a paint store for several years, did a loooot of color matching by eye.
I had no idea the builder we had was going to use flat inside. I fucking hate it, the patches we've painted over with THE EXACT same paint never match because we are brushing it on and not spraying.
We added onto our house and our contractor suggested flat and I vetoed it. Eggshell at minimum, please! I don’t do trendy. So happy to have insisted.
All of our trim is in Swiss Coffee though, lol. The funny thing is, I’d much rather have dark wood trim but that would cost a fortune. Maybe someday I’ll improve my DIY skills enough and do it myself.
If you have kids or pets, or just have a tendency to be a clumsy person yourself, then glossy is much better from a practical standpoint. So much easier to clean with less risk of rubbing the paint off the wall.
To be fair, I don't have much of an eye for style so it suits me just fine.