Lighting and Colour Temperature

In lighting, colour temperature describes the bias of white light, meaning it’s either a cool white, warm white, or something in between. The Kelvin scale is used to describe this bias. For instance, a 4000K bulb has a cool-white hue, while a 2700K bulb is warm white.

To understand this theory, you only need to remember that higher numbers mean a cooler light and lower numbers are warmer. So, how does this affect your choice of lighting in the home?

Warm Light for Chilling Out and Cool Light for Working

It’s well known that warm light relaxes us and cool white light keeps us awake. Not so long ago, homeowners could only buy warm-white incandescent bulbs for the home and maybe a cool-white fluorescent tube for the kitchen. But things have become more sophisticated in recent years. Now we have LED bubs as well as the “energy-saving” fluorescent bulbs that preceded them. And they come in all colours.

Warm White

With modern technology, it’s possible to mix and match your lighting to suit each room. Thus, you’d probably go for a warm white light (2700K to 3000K) in the dining room, living room, entrance hall, or bedroom. These are the rooms you want to relax in. Warm white is also more welcoming, so it’s ideal for hallways and exterior lighting at the front of your home.

You can use warm white light to illuminate pictures and paintings, but remember the colour of light affects how the picture looks. Hence, warm lighting is good for illuminating red, orange, brown or yellow colours, but it might detract from blues, greens or violets.

Cool White

Cool white light is the classic choice of “task lighting”, so you might choose it for a kitchen, an office, a utility room or a garage. This type of blue-white light is what keeps us awake when we stare at PC screens or phones late at night. Luckily, plenty of devices like the Apple products at let you switch the backlighting to warm-white light, which is less disruptive to sleep.

Just as warm-white light is welcoming, so cool-white light is unwelcoming. For that reason, it works well in security lighting, where its slightly stark appearance acts as a deterrent. Cool-white light also tends to look brighter to human eyes, so it’s doubly effective. It makes a good choice of reading light, too, but only if you don’t intend reading yourself to sleep.

Daylight White

Daylight white usually varies between 5000K and 6500K on the Kelvin scale. It has a cool white hue that resembles the natural light we see outside in the middle of the day. Like ordinary cool white light (e.g. 4000K), it makes an excellent choice of task lighting.

Daylight white also has a therapeutic benefit, especially when it contains most or all colours of the visible spectrum. Look for a high CRI specification into the 90s for that. This type of “full spectrum” light can help combat problems like seasonal affective disorder (SAD) or depression.

Choosing the right lights for your home keeps you productive and promotes well-being.