Color temperature is the first thing a customer notices after the lights come on. Get it wrong and the space feels cold, yellow or just off, even if the light levels are perfect. Here is how to pick the right Kelvin for commercial and industrial jobs, and what CRI adds to the picture.
What the numbers mean
Color temperature is measured in Kelvin (K). Lower numbers look warmer and more yellow. Higher numbers look cooler and more blue. It describes the color of the light only. A 5000K fixture is not brighter than a 3000K fixture of the same lumen output, it just looks different.
Where each color temperature fits
| CCT | How it looks | Typical commercial uses |
|---|---|---|
| 3000K | Warm white, similar to halogen | Restaurants, hospitality, lobbies, some outdoor and decorative work |
| 3500K | Neutral warm | Offices, schools, retail that wants a softer feel |
| 4000K | Neutral white | Offices, retail, healthcare, schools, general commercial |
| 5000K | Daylight white | Warehouses, manufacturing, garages, parking, shops, gas station canopies |
| 6500K | Cool, slightly blue | Specialty tasks; often feels harsh for everyday spaces |
Rule of thumb: people spaces lean 3500K to 4000K, work spaces lean 4000K to 5000K. When in doubt on an interior job, 4000K is the safe middle.
Indoor jobs
Offices, classrooms and medical spaces typically land at 3500K or 4000K. It is comfortable for long hours and renders skin tones and paperwork well. LED flat panels and troffers for these spaces usually ship in 3500K, 4000K and 5000K options.
Warehouses, distribution centers and production floors typically go 4000K or 5000K. Cooler light reads crisp on labels and fine detail, and most customers expect that look in an industrial space. That is the usual choice for LED high bays and strip lights.
Retail is a judgment call. Grocery and big box stores often use 4000K to 5000K. Boutiques, furniture and food service tend toward 3000K to 3500K to feel warmer.
Outdoor jobs
Parking lots, wall packs and area lights are most often 4000K or 5000K for visibility and camera performance. Some municipalities and dark sky ordinances ask for 3000K or lower for outdoor lighting, so check the local code before ordering a whole site.
Gas station canopy lights and parking garages are usually 5000K. It looks clean and bright, and it matches what drivers expect at the pump.
Match the room, not the catalog
- Do not mix CCTs in the same space. A 4000K fixture next to a 5000K fixture is obvious from across the room.
- On partial retrofits, match what is staying. Check the existing lamps before you order.
- Use selectable CCT when you are unsure. Many fixtures let you switch between 3500K, 4000K and 5000K on site. See selectable wattage and CCT.
- Show the customer first. On a big job, hang one fixture and let them sign off on the color.
CRI basics
Color Rendering Index (CRI) tells you how accurately a light source shows colors compared to a reference source, on a scale up to 100. It is a separate spec from color temperature. You can have a 5000K fixture with a CRI of 70 or one with a CRI of 90.
| CRI | What to expect | Typical uses |
|---|---|---|
| 70+ | Fine for general visibility | Warehouses, parking, outdoor, industrial |
| 80+ | Good, natural looking color | Offices, schools, most retail, general commercial |
| 90+ | Very accurate color | Paint, auto body, print, galleries, high end retail, medical exam |
Most commercial LED fixtures today are 80 CRI or better. Higher CRI usually costs some efficiency, so only push for 90+ where color accuracy actually matters to the work.
Rebates and color: CCT and CRI can affect whether a product qualifies for DLC listing in some categories. If your customer wants a rebate, check the exact model and find out if there are rebates in your area.
Fixtures with selectable color temperature
Set the CCT on site and stop guessing before you order. Contractor pricing on every fixture.
See selectable CCT