We need pics and you do not test wall color on a wall but on poster board painted with 2 coats of the paint you want to test . The move the boards around to the different spaces BTW paint is not how you lighten up a space that requires lighting and IMO all LED 4000K.

You absolutely test paint on the walls in large swatches; sample boards are good to get a feel for a color but the final test should be on the wall (primed first to cover any old paint that will affect the new color). And 4000K lights have nothing to do with the effects of natural iight exposure on paint -- who leaves their lightbulbs on all day?

I prefer paint on the poster boards, however, you can paint on walls,if, you primer those walls white first. Never put paint on top of the existing paint, because, you will not get accurate color. Light bulbs are important, because, you want the walls to look the same in the daylight, as they do when you put lights on later in the day. One example, I just bought a new floor lamp. It came with 2700 led edison type bulbs. I put it all together, and turned on the lights, and my aqua walls, turned all gold. I turned it off pretty darn fast, and went back to the computer to order all new edison light bulbs in 4000. They should come tomorrow, and I cant wait. Same with my hall. After storm damage, I changed the lighting in the hallway, and put in all 4000 bulbs. My hall is also the aqua color, and the paint had always had a golden cast to it. It now shows the exact color on the paint chip.

When did you paint? If less than about 2 days, just chill and get back to us later. It takes a while for the various pigments to dry and color to settle down. I just had the opposite problem recently - color looks wonderfully vibrant for a few hours, a day maybe, then fades and turns blah and dingy. Unless you know it is just waaayyyy off, then proceed to seeking out alternatives.

"And 4000K lights have nothing to do with the effects of natural iight exposure on paint -"

Note the natural light exposure comment. OP is dealing with skylights. No question lightbulbs affect paint color when the lights are on, but lightbulbs are not going to counteract the effects of natural light streaming in during the daylight hours and affecting the wall color. Unless you leave the bulbs on all day, and even then the effect is questionable, depends how strong the natural light is.

You can pick paint colors from sample boards without testing the color on the walls unless you have a fair amount of texture on the walls and smooth sample boards. When dealing with an orange peel texture I usually spray orange peel texture on my test boards prior to painting, but rougher textures really do need to be painted on the wall.

You want to live with the colors you select for several days. You want to look at the color on different walls and at different times of the day. I don't have rooms in my house that I only want to look good in the daytime or in the evening. I want them to look good regardless of the time of day and if I have sunlight streaming in or lights turned on.

The color of your lighting is a personal decision, but there is evidence that people living in the Southern parts of the US prefer cooler lighting than those in the Northern states and Canada.

I lived in San Diego for 30 years and strongly prefer 5000k lighting. Patricia lives in Canada and strongly prefers 4000k. If my memory serves me correctly both Patricia and I lean toward modern design. My sister has lived in Pennsylvania and New Jersey all of her life and strongly prefers 2700k and another sister of mine, who has lived in PA her whole life likes 5000k and my sister in law who also lived her whole life in PA like 3000k, so obviously geography isn't the only answer. I think the colors you love, the style of your home, the type of work or hobbies you have done and eyesight also influences your preference.

My favorite color is purple. I have purple undertones in the taupe paint on the walls and purple in the artwork I display. If you add yellow to purple you get mud. Even 4000k lighting dulls my purples. Most of my hobbies also require really good lighting. My sister who also likes 5000k lighting has had detached retinas, cataracts and worked as a physician before she retired. Physicians often prefer 5000 k or higher lighting. Surgical lighting is generally 6500k. This is what they are used to having and yellower light may feel inadequate. My sister-in-law who likes softer white has her home decorated with a more old fashioned, classic country style with cornflower blues and peaches, yellows and creams. 5000k was too bright and too clear with her furnishings and colors. It felt stark. My other sister, the one who likes her Edison bulbs and 2700 k lighting also likes antique furnishings and older style homes. She lived in a 200 year old 4 square, then a newer 4 square and then built her dream home - a Tudor style home. She has dark rich walls and dark rich woods and her colors are fall colors, deep greens, golds and orange reds. 2700k lighting fits her styles and color preferences.

4000k is often listed as the ideal lighting, just like Oxford White is often the go to white for trim. In most homes it will be okay. It doesn't mean it is the best choice, it just means it generally works, so if you don't know what to get or you can't test before you paint it is a safe choice.

Those are very good comments about the color of the light. I also read somewhere that if your kitchen has wood cabinets 3000K is preferable whereas 4000K is better for white kitchens. That makes sense to me, a warmer light enhances the beauty of wood. Seems like it would apply to the rest of the house, along the lines of what you said about the style of the house/preferred color schemes. I don't like 4000K -- I've tried it, and it is too harsh FOR ME. I'm happiest at 3000K, but I have tried 3500K and that was fine, too, but stuck with the 3000K. Still, lightbulbs are not going to magically counter the effect of sunlight/exposure, and a blanket statement of everything should be 4000K is just that -- a blanket statement that doesn't apply to everyone or every situation.

I'm sticking to my guns about sampling paint on the wall, though -- subtle nuances often manifest with really large swatches. Maybe others aren't so sensitive to small color differences, IDK. Sample boards are good to narrow it down, but there were a handful of sample boards I quite liked but when I slapped on the walls = no go.