Blue paint is the diva of the paint world. Stunning. Dramatic. Completely unwilling to “just be chill” in whatever random lighting situation you throw at it.
And if you’ve ever picked a blue that looked perfect on the paint chip… only to watch it dry into either sad cave navy or electric pool toy, welcome. You’re among friends. (Ask me how I know. Actually don’t. I still have emotional scars.)
The thing that usually causes the heartbreak? A tiny little number most people ignore: LRV.
The only four things you really need to do (so you don’t cry later)
If you do nothing else, do these:
- Figure out your light situation: Is the room north/south/east/west facing?
- Pick an LRV range that matches that light (I’ll give you the cheat sheet in a sec).
- Choose your undertone lane: gray, green, or violet.
- Test it like a responsible adult (I’m saying this as someone who has not always tested like a responsible adult).
Because blue doesn’t “kind of” change. Blue commits.
LRV in normal person language
LRV (Light Reflectance Value) is just a measure of how much light a paint color bounces back into the room.
- 0 = pure black
- 100 = pure white
So if a color has a low LRV, it’s basically hoarding light like a toddler hiding snacks under the couch. It’s not giving that light back.
And blue especially deeper blues already tends to absorb light, which means it often looks darker on your wall than it did on the chip. That’s how you end up with “dreamy coastal navy” turning into “why is my living room a bat cave?”
You can usually find the LRV on the back of the paint chip or on the manufacturer’s website. (If you can’t find it, that’s annoying, and you’re allowed to be mildly offended.)
The LRV ranges that actually help you choose a blue
Think of LRV like the volume knob on your blue.
Dark blues (LRV 5-20)
Moody. Fancy. Potentially life ruining in a dim room.
These are best when you have lots of natural light or you’re using them as an accent (like an island, built ins, a powder room you want to feel like a tiny jewel box). In a low light room? They can read nearly black, and not in a cool way more like “did we forget to pay the electric bill?”
Medium blues (LRV 30-50)
This is where a lot of “real blue” lives still saturated, still bold.
They usually need decent lighting to stay happy and not turn muddy. Great for statement walls, cabinetry, offices where you want a little drama but not full haunted house.
My favorite starting point (LRV 57-65)
If you’re overwhelmed, start here. Truly.
This range tends to give you a shade like Sherwin Williams SW 6242 that still looks like blue in normal lighting without going full baby nursery pastel. It’s the “I want blue walls but I also want to see my furniture” range.
Light blues (LRV 65-75)
Bright, airy, space expanding.
Amazing for smaller rooms or spaces you want to feel open. The catch: in a super sunny room (hello, south facing), some of these can wash out and start whispering “I might actually be off-white.”
So yes: numbers first, feelings second. (But don’t worry, you still get feelings. It’s paint. Feelings are inevitable.)
Window direction: the part no one wants to deal with (but you have to)
Your room’s window direction is basically the boss of your paint. The paint is just trying to keep its job.
North facing rooms
North light is cooler and weaker. It can make blues feel… a little tired. A little gray. A little “did I accidentally choose denim?”
In north facing rooms, I usually like higher LRV blues (think 60-70) so the color doesn’t sink into gloom. And I’m cautious with super gray leaning blues here north light can make them look dingy fast.
South facing rooms
South light is bright and warm and honestly kind of rude because it makes everything look better than it deserves.
You can often go darker in here and still have the color read rich instead of bleak. But very high LRV blues can get washed out midday.
East facing rooms
Bright mornings, shadowy afternoons. It’s like the room has a productive morning routine and then fully gives up by 2 PM.
I tend to like slightly green leaning blues here because they stay friendly as the day shifts.
West facing rooms
Soft light earlier, then warm golden “sunset mode” later which can pull out undertones and make some blues slide toward teal.
If you’re testing paint in a west facing room and you don’t look at it around 4-6 PM, you’re basically skipping the plot twist.
Undertones: the secret flavor in your blue
Two blues can have the same LRV and still look wildly different because of undertones. Undertones are the background singers that suddenly step forward and grab the mic.
Gray undertones
These can look soft and sophisticated when the light supports them.
In cooler rooms (north facing especially), gray undertones can tip into “why does this look purple-ish and depressing?” territory. Not always. But enough that I tread carefully.
Green undertones
My personal “safest bet” for most homes.
They tend to feel warmer and more livable and they’re less likely to go icy. The only caution: in west facing rooms they can lean more teal than you expected (sometimes gorgeous, sometimes… not what you signed up for).
Violet undertones
These can look rich and complex like the blue has a college degree.
But in shadows, violet undertones can read more purple than you planned. If you love that, amazing. If you don’t, test it first unless you enjoy surprise lavender walls.
Your bulbs and sheen are quietly messing with you
Lighting isn’t just windows. It’s also your light bulbs those little liars.
- Warm bulbs (around 2700K) can mute blues and pull out gray.
- Cooler bulbs (4000K and up) make blues look sharper and cleaner (sometimes too sharp).
And sheen matters too:
- Matte tends to absorb light, so colors look deeper.
- Satin reflects more light, so colors can look a bit brighter (and it’s easier to wipe down, which is why kitchens love it).
Test your color with the sheen you’ll actually use and the bulbs you actually live with. Not the imaginary bulbs you “might swap someday.” (I say that as someone who has lived with “temporary” bulbs for four years.)
Test before you commit (because store lighting is a catfish)
Paint store lighting is the department store mirror of home decisions. Flattering. Bright. Not reality.
Here’s my simple, non-fussy test:
- Paint a big sample (at least a 12″ square) on the wall.
- Do two spots: one near a window, one on a darker wall.
- Live with it for 24 hours: morning, afternoon, night, lamps on, everything.
If it stays pleasantly blue instead of going gray, neon, or weirdly purple at night congrats. You found a keeper.
Two ways people accidentally make blue look “off”
1) Forgetting trim contrast
Trim is like eyeliner. It defines everything.
If your trim and walls are too close in depth, things can look muddy. I like a noticeable difference especially with deeper blues. Crisp white trim with navy walls is classic for a reason.
2) Forcing a dark blue into a dark room
A low LRV blue in a windowless room doesn’t automatically equal “moody shades in small rooms.” Sometimes it equals “storage closet chic.”
If you love dark blue but your room has the lighting of a submarine, use the drama strategically: cabinetry, a vanity, built ins, wainscoting. You can still get the vibe without sacrificing your will to live.
The quick “put it together” cheat sheet
If you’re standing in your hallway right now staring at paint chips like they’re going to reveal your destiny, here’s the move:
- Find your window direction (N/S/E/W).
- Pick an LRV lane:
- dim/cool rooms → aim higher (around 60-70)
- bright/sunny rooms → you can go mid range or darker
- Choose 2-3 blues in that range with different undertones (one greener, one grayer, maybe one wildcard).
- Test them on your wall for a full day.
Then make blue prove itself in your actual house, with your actual light, and your actual life happening around it.
Because the goal isn’t just “pretty on a chip.” The goal is blue you still love on a Tuesday at 7 PM when the only light is your lamp and a half dead candle you forgot to blow out.