Let’s start with the basics.
Color Temperature. What the heck is it?
If you want to be technical, the color temperature of a light source is the temperature of an ideal black body radiator that radiates light of comparable hue to that of the light source…blah…blah…blah.
Really though, ain’t no body got time fo dat.
Simply put, color temperature refers to the comparable hue or color a light emits within the visible color spectrum.
It is measured in kelvin (K), the unit of absolute temperature. Pure, bright white light is made up of all colors on the visible light spectrum with warmer hues being on the low end (3000K or less) and cooler or bluer hues on the higher end (5000K or more). Neutral white makes up the difference between the two and is the closest to the light we are used to seeing.
We’re not trying to say your patio, desk, or sofa will look like a Smurf (unless that is the look you’re going for ) but you will notice a slight hint of blue hue in the illumination. In any case, we can make that happen too.
In fact you can specify any color temperature your heart desires as well as red, green, or blue.
Back to color temperatures.
arm White (2700K +/- 300K)
Warm white is best utilized in living spaces such as bedrooms, libraries, and bathrooms because it mimics the glow of traditional incandescent bulbs which have more red and orange wavelengths which bring out flesh tones and the richness in fabrics, especially those warmer in color.
eutral White (4100K +/- 500K)
Neutral white is ideal for use in task lighting, office spaces, and hospitals because it allows people to see things clearly because of its “true to color” characteristic white illumination.
ool White (5700K +/-500K)
Cool White is ideal for use in outdoor, industrial, and warehouse applications because mimics daylight on the clearest day at noon. It also looks the brightest of all the color temperatures and is the standard for diodes Noribachi uses. Cool light sources are heavy in blue and green wavelengths
Color Rendering Index (CRI)
The Color Rendering Index refers to the quality of color perception that a light source provides. Scaled from 0 to 100, daylight is considered to be 100 CRI and the standard against all artificial lamps.
LEDs have a high CRI, usually in the range of 75-95. because of their “white” illumination.
Color Rendering Index Is the ability of a light source to skin tones, room finishes, or fabrics look “natural.”
In an environment with a CRI rating greater than 50, occupants need to roughly identify or differentiate colors in a space.
A CRI rating greater than 80 is required for spaces where people need to communicate with each other regularly or if food is involved. This includes offices, schools, commercial spaces, art galleries, museums, studios or where skin tone is important.
A CRI rating greater than 90 is required in a environment where color/tone application, color matching tasks such as paint mixing will be done. Despite high CRI ratings, they are deficient in blue and violet wavelengths.
“Always design a thing by considering it in its next larger context – a chair in a room, a room in a house, a house in an environment, an environment in a city plan.”
Eliel Saarinen, Finnish-American architect
Creating Environments Using Color Temperature and CRI as a Guide
Let’s take a specific area–for example an office.
Overall, the client wants the space to be conducive to productivity and prevent fatigue while keeping the space cozy so that guests are welcomed and relaxed when they visit. Our client tells us that the office area has workstations surrounding a waiting area for guests, the walls are white and their furniture is a mixture of leather and fabric in the warm color palette.
To approach this project, I must take into account what the client wants while recommending the right solution considering everyone in the environment. As a designer, I want to consider the factors are existing and which I will be adding (lighting) or subtracting.
From what I know using the information above, there are competing factors at play–the client wants the space to be productive for employees, yet be cozy for clients. I also want the lighting to compliment the elements that are already here such as furniture.
My first recommendation would be to utilize neutral white overhead lamps because it is a happy medium between warm white and cool white. It will bring in all colors of the spectrum nicely so that flesh tones look natural, the warm palette of the furniture will not look dull, and because it is closest to the “white” we are used to seeing during the day, it is comfortable for our eyes and in fact prevents fatigue.
My second recommendation would be to add task lighting at workstations so that individual employees can add or subtract the amount of light they want to use to focus on certain areas of their space. These should utilize warm white LEDs because they don’t need to be bright like cool white, but enough for reading and writing.
One way to set or change the mood of a room is to incorporate dimming so the amount of light can be dialed in to the preferred intensity. During the day, the lights could remain at full brightness while in the evening they can be dialed down to 50 percent and task lighting can be used. In addition to creating a comfortable office environment, it helps save on energy because you’re only lighting areas that really need it.
If you have a scenario or setting you want me to analyze, please let me know and I’d love to help you pick out the right lights to accent your rooms!