This is so common it has a name, it’s called banner blindness.
One of the important aspects of interface design is supposed to be not showing alerts for everything, so that when they pop up you feel compelled to pay attention.
Not long ago a nurse killed an older woman by giving her the wrong medicine; she took accountability but called out that the software they use provides so many alerts that (probably unofficial) policy was to just click through them to get to treating the patient. One of those alerts was a callout that the wrong dosage was selected and she zoomed right by it out of habit.
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.