Warm bulbs, cool bulbs & everything in between…
Remember when you’d go shopping for light bulbs and all you had to think about was wattage? Not anymore. Now, it’s ALL about KELVINS.
Of course, wattage still matters, as do lumens and CRI. But these days, when it comes to choosing a light bulb that ENHANCES colours, Kelvins are the main consideration.
Interior lighting is used to make up for the light coming from the outside; either the AMOUNT, QUALITY, or TEMPERATURE of it. Part of this is covered by KELVINS. Once you get on more intimate terms with him, you’ll realize he’s not such a bad guy – you might even become besties.
Light Bulb Temperatures (Kelvins) & Paint Colours
KELVINS (shown as K on the light bulb package) are the measurement of the TEMPERATURE of light.
The above representations are approximate
While there’s an even LARGER range of Kelvins than shown above, today we’re focusing on the ones MOST COMMON ones – not those used in igloos and saunas. YES, I’m talking to the men out there who LOVE their light bulbs as cold as their beer – these cold bulbs have GOT to GO!
But a few notes before we start…
- There are many ways of grouping Kelvins – this is how I’ve chosen to group them for learning purposes.
- I can’t touch on every type of bulb and temperature/wattage/etc… I can only advise on the most COMMON bulbs and Kelvins, otherwise, we’ll BOTH lose our minds.
- I’m not a LIGHTING expert, I’m a paint colour expert who happens to put two & two together.
- When you’re done, you’ll find a link at the bottom of this page called ‘How the CRI of Light Bulbs Affects Paint Colours’ – it’s a MUST READ!
Also, thank you to all of my Online Paint Colour Consulting clients who send in their photos – I love you!
2500-3200K LIGHT BULBS
This is a range we’re pretty familiar with as it’s the range of most incandescent bulbs.
The temperature of the light in this range is warm – yellow. And while some bulbs dip down to 2200K (ie: Edison bulbs), 2700K is pretty average.
The lower the number is, the WARMER the light is. WARMER in this range = YELLOW (the lower you go, the more orange you’ll get, then red). For most people, 2500K is the starting point.
WARM PAINT COLOURS & 2500-3200K BULBS
- WARM PAINT COLOURS will be enhanced by these warm bulbs as they lean into each other.
- The lower the Kelvin number is, the warmer your paint colour will look. If you go TOO low in Kelvins, you’ll start picking up pink-red. I recommend no lower than 2500K.
- Warm paint colours often look their best between 2700K and 3200K.
COOL PAINT COLOURS & 2500-3200K BULBS
- COOL PAINT COLOURS will be toned down and muted by this warm light.
- Cool colours that look crisp and fresh in white or cool light, will lose this edge in warm light. This isn’t a bad thing, as what was once a cool clean colour in the day, can look soft and subtle in the evening. Just note that you can expect tweaked undertones as the colour will be distorted.
- Some paint colours with a bit more blue in them can even look a bit greenish under the warmth of lower Kelvin bulbs.
In this home office below, Sherwin Williams Sea Salt looks even MORE beautiful with warm light shining on it!
Did you notice the shift in how the paint colour looks from left to right?
In this living room (below), look at the paint colour on the RIGHT side of the photo and then look at the colour above the fireplace. Based on the visible shift of the paint colour (Benjamin Moore Stonington Gray), I bet these are 2700-3200K bulbs!
If you want a room with a cool colour to look clean and crisp at all times, you may want to choose a bulb with higher Kelvins. But it’s not all about your paint colour, make sure it’s a light you’re comfortable LIVING in.
3300-4200K LIGHT BULBS
TEMPERATURE: BRIGHTER WARMTH TO NEUTRAL WHITE
Light bulbs around 3300K will still have a SUBTLE warmth to them, but their light will be LESS warm/yellow than the lower Kelvins. These Kelvins can come across as a bit brighter and whiter looking. However, this slightly brighter white doesn’t mean you have higher lumens (even though it might look like it).
As the Kelvins get higher, the warmth starts disappearing to the point where at 4000K you have a relatively ‘neutral bright white’. This light isn’t necessarily warm or cool, it’s more ‘neutral’ (although compared to warm bulbs, it can look pretty darn cool).
While this is a POPULAR range for many households, personally, I use 2700-3000K in almost ALL of my fixtures – I err on the side of warmth.
BTW, I will NEVER put a bulb higher than 3500 in my own home…just sayin.
WARM PAINT COLOURS & 3300-4200K BULBS
- Around 3300K, warm paint colours will look soft and warm, as they should. However, they’ll have a bit more brightness compared to the 2700K range (and LESS warm than they would in the lower range).
- 3300-3500K won’t ENHANCE warm colours the way the lower range can, and can still be quite pretty if the 2700K range is too warm/yellow for you.
- As you get closer to 4000K, you’ll gradually lose warmth. This warmth is replaced by a whiter light. Warm colours start getting a bit nervous in this range as the light isn’t catering to them as much.
See this GORGEOUS laundry room makeover HERE
In the higher end of this range (I’d say 3800-4200K), warm paint colours can sometimes look a BIT off, as this whiter light almost seems a bit cool; like it’s going slightly against the intentions of warm paint colours. It’s one thing to add contrast with paint colours, but a WHOLE different thing to try it with light bulb temperatures. Even though 4000K isn’t COLD or blue, its lack of warmth can make it seem cold.
ANOTHER reason for this is because, for many years, we were used to the warmth of 2700K bulbs – incandescents.
Because of this, even a bulb that’s not cold, but not overly warm either, can make colours SEEM a bit off. This could just be because the temperature of the light isn’t as familiar.
Sherwin Williams Big Chill
COOL PAINT COLOURS & 3300K-4200K BULBS
- In the 3300-4200K range, cool paint colours start to perk up a bit, but will still be a bit toned-down or slightly distorted in the lower end of this range. This isn’t necessarily a BAD thing, as toned-down cool colours can look VERY pretty, just different than they would in a COOLER light.
- Cool paint colours enjoy the 3500K+ range, as it plays off the more crisp, clean look of cool colours; especially as the Kelvins get higher. But remember, like north-facing light, this will compound the cool look of an already cool-looking room, as you won’t be adding any warmth for balance.
I appreciate how nice a cool colour LOOKS in the 4000K+ range, but I don’t appreciate how the room FEELS (but you do you).
Sherwin Williams Pure White
Funny enough, they (you know, ‘they’) say that the BEST light for paint colours to look their most true is 5000-6000K with a CRI of 100. Okay, I get the 100 CRI bit (it’s slightly excessive, but so is my wine consumption, so who am I to judge)…
…but 5000-6000K? Do you have ANY IDEA HOW FREAKIN’ COLD THAT IS?
If you’re MORE concerned with how your paint colour looks (and less with the visual temperature of the room), and enjoy a mix of warm and cool tones, you might choose bulbs approx. 3500-4000K. This range could offer a more balanced light (erring on the slightly warm side at 3500).
Now, do you want to know what happens as we carry on down this path into higher Kelvins? I run out of photos and there are a few reasons for that…
1. Interior photos are usually best taken with lights OFF (as long as there’s adequate exterior light).
2. I ONLY use photos from my E-Design clients – REAL HOMES for reality-based advice.
2. Not as many people use cool bulbs compared to warm bulbs. And if they do take a picture, it doesn’t always translate well.
How the CRI of a Light Bulb Affects Paint Colours
4300-5000K LIGHT BULBS
TEMPERATURE: A RELATIVELY NEUTRAL WHITE TO BLUE
Hubbies worldwide REJOICED when they introduced cool white-blue LEDs! For some reason, many men love these cool-tinted bulbs. On the other hand, MOST women find them too harsh and unfriendly or clinical (like, ‘just lie down, cover your lower body with this sheet and place your heels right here’ kind of clinical). Personally, I would only use this temperature range in my garage… Nah, I still wouldn’t (but that’s me – YOU DO YOU!).
BTW, that’s a generalization based on experience, just like most men don’t like to paint wood, whereas many women already have their paint roller wet!
For a room like this bathroom (below), a cool light/slightly higher KELVINS will help the blue paint colour look crisp and fresh. However, this same bulb could make the warm white trim look a bit dingy. It’s a balancing act!
Personally, I think 4300-5000K is damn cold (particularly 5000K). If you choose bulbs in this range, you’re looking at a cold blue-white light that is MOST similar to a clear, bright, north-facing day, (wearing blue-tinted glasses). The closer you are to 4000K the more neutral/less blue the light will be, the closer you are to 5000K, the cooler or bluer the light will be.
WARM PAINT COLOURS & 4300K-5000K BULBS
- Whereas some cool paint colours can look pretty in warm light, warm paint colours will look flat and distorted in this cool white-blue light.
- You may find that using higher Kelvins in the bathroom*, can cast a GREEN glow onto your skin – which is great if you’re Shrek.
*I DO understand that for those who need to see better, a brighter cooler bulb can be helpful. But if you wonder why your cream-coloured walls look a little peaked and your face looks a tinge green, well, now you know why.
COOL PAINT COLOURS & 4300K-5000K BULBS
- Cool paint colours will respond well to cool white-blue light, just as warm colours respond well to the 2700K range. If you are a lover of everything crisp, cold and clean, this could be the Kelvin for you. Just don’t tell your partner about this amazing ‘Kelvin’ fellow you’ve been introduced to.
I can’t tell you from personal experience how paint colours will react to cool-toned bulbs because I would never…ever…do this to my home. I know this is a personal preference, and I don’t mean to sway you…wait, yes I do. You subscribe to my blog to learn about what looks good and this ain’t it. Unless that is, you live in a commercial space, workshop or institution.
So, where is a 5100K+ bulb most popular?
- commercial applications
Some people also use them in their bathrooms (great for tweezin’ those nose hairs), but it can cast a greenish light on the skin. Energizing, yet not ideal.
A beautiful bathroom like this would be DESTROYED by the wrong Kelvins!
I’m sure there are men WORLDWIDE pinning a photo of my face to a dartboard, but I’m just keepin’ it real. For the MAJORITY of homeowners, 5100K+ isn’t a comfortable light to live in.
WARM PAINT COLOURS & 5100K+ BULBS
- Warm paint colours will look greatly distorted in 5100K light as it doesn’t have yellow/orange/red in it to PLAY with warm colours (blue light actually will absorb red).
COOL PAINT COLOURS & 5100K+ BULBS
- Cool paint colours will be in their glory when using bulbs with this high of a number – AS WILL ELSA! (a la Frozen)
A blue paint colour like Sherwin Williams Niebla Azul (below) is going to be in its GLORY in the higher Kelvins, but you better WATCH that warm white trim!
Light Bulbs, Kelvins & White Paint Colours
Because white paint colours reflect the most light (having the highest LRVs), they’re SUPER responsive to the Kelvins you choose.
If you give a paint colour with a high LRV a light that is tinted with yellow, blue or another colour, your walls will do one of the following:
- reflect some of that colour back at you
- the undertone in your white can be muted or distorted
WARM WHITE PAINT COLOURS & KELVINS
Warm white paint colours will have undertones of yellow, orange or red. As mentioned above, if you give white paint colours a light that casts a particular hue, this will affect your paint colour.
- If you choose lower Kelvins for your warm white, your white will be enhanced and look that bit warmer.
- Choose moderate Kelvins for your warm white and it could look well-balanced based on its intentions/undertones.
- However, start dabbling in the higher Kelvins with warm whites and you could get murky-looking walls with disturbing undertones.
In this next space, I assume these bulbs are approx 3200K…
See this GORGEOUS laundry room makeover HERE
TRUE WHITE PAINT COLOURS & KELVINS
Because true white paint colours don’t lean warm or cool, they’re very susceptible to tossing back what you throw at them. Give them a warm light, they’ll give it back. Give them a cool light, they’ll give it back.
In this bedroom below, Sherwin Williams High Reflective White looks gorgeous in natural light. If the bulbs have a lower Kelvin, you can expect the walls to look warm. If the bulbs have a higher Kelvin, you can expect the walls to pick up a blue hue.
COOL WHITE PAINT COLOURS & KELVINS
Cool white paint colours will have undertones of blue, violet or green. Again, the Kelvins you use can GREATLY affect how your paint colours looks!
- Give your cool white paint colour a bulb with higher Kelvins, and the undertones of your paint colour can be ENHANCED.
- Choose a more moderate Kelvin for your bulbs and your cool white could settle in just as expected (not glorified OR distorted).
- However, give cool white paint colours a bulb with a yellow hue (lower Kelvins), the cool undertone of your white could be distorted. But unlike WARM colours and HIGHER Kelvins, this isn’t necessarily a bad thing. This combo can actually add a bit of balance, as cool colours that are dulled can still look very pretty (just a bit different from their original intention).
In this gorgeous powder room, Benjamin Moore Super White (which is a cool white), looks a touch warmer with these bulbs. Again, while warm colours can look considerably off in cooler light, cool colours can look pretty in a warmer light!
When opposites DON’T attract
Now, I’m sure you can figure out which Kelvin you and your paint colours love to live in, but what happens when you and your PARTNER like opposite ends of the scale? Well, you could flip for it, or you can check out these tips…
- If you have a partner who LOOOOVES the cool white-blue light of the 4500K+ range and you’re more of a warm white lover (2700K range), 3500k can be a reasonable place to settle. Reasonable meaning it caters slightly more to the warm end of things than the cool end. 4000K is actually more reasonable. #imslightlypassiveaggressive
- If you have mostly warm colours in your home, they could decide it for you, as warm colours do best in warmer, lower Kelvins. Remember, warm colours can actually look BAD in cooler, higher Kelvins.
- If you have mostly cool colours in your home, they could decide for you. Cool colours look their best in MODERATE Kelvins (let’s say, 3500K) or higher ones. HOWEVER, keep in mind, that unlike warm colours, which can look TERRIBLE in cool light, cool colours can look quite pretty in warmer, lower Kelvins as well – just a bit different.
It all comes down to the type/temperature of light you’re comfortable LIVING in.
- If you prefer ONLY cool colours and a cooler light, you might prefer bulbs with 4000K+. However, you may want to add balance with texture and warm accents, otherwise, your room could look a bit stark and icy.
- In my experience, many of us enjoy a softer, warmer-looking environment – it’s a more inviting look. Sure, we can add a bit of freshness to that, going up to the 3500K range, but BEYOND that is unfamiliar territory. Again, this goes back to the fact that many of us were raised with incandescents.
- In my own home, I don’t have a variation of more than 500K between fixtures IN a room and BETWEEN rooms. This way, I can add a bit more function where needed (3000K in my task lights) while keeping softness in other fixtures 2700K). This helps a room feel balanced and flowing when all of the lights are on, without having a warm light battling a cool light. Sadly, the cool light will ALWAYS win because they tend to look darn bright!
There you have it! Do you feel any BRIGHTER? Are you positively GLOWING with new knowledge and feeling like a real chLAMPION? You should, you learned a lot today!
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The CRI of Light Bulbs and How it Affects Paint Colours
ORIGINALLY PUBLISHED IN 2021, UPDATED FOR YOU IN 2022!