Light spectrum, the different colours of light

Have you ever wondered why the sky looks blue, why sunsets are orange and pink, or why some indoor lights just feel … wrong? Let’s take a trip into the world of light!

What is light, really?

Light might look white to our eyes, but it’s actually a rainbow in disguise. White light is made up of many different colours, which together form the light spectrum. Think Red, Orange, Yellow, Green, Blue, Indigo, Violet. You’ve probably seen this in action when light passes through a prism or in a rainbow when it’s raining and the sun shines at the same time.

Each colour in the spectrum has a different wavelength:

• Red light = long wavelength

• Blue/violet light = short wavelength

Photo by Zdenek Machacek on Unsplash 

But why does the sky look blue (And not rainbow)?

When sunlight hits the Earth’s atmosphere, it bumps into tiny molecules in the air. These molecules scatter the light, but they don’t scatter all colours equally. Shorter wavelengths like blue get scattered much more than the others. That’s why the sky looks blue during the day!

Why are sunsets and sunrises orange and red?

At sunset (or sunrise), the sun is lower in the sky, so its light has to pass through more air to reach your eyes. By the time it gets to you, most of the blue light has already been scattered away. What’s left? The reds, oranges, and pinks. Which makes those beautiful sunset and sunrise magic!

Daylight vs. bad electric light

Not all electric lights are created equal! Only high-quality daylight lamps are designed to have the right light intensity and spectrum that compensates for the lack of daylight from sunrise to sunset.

Daylight (the gold standard)

• Full of all the colours of the spectrum.

• Feels natural and comfortable to our eyes.

• Helps regulate our body clock (circadian rhythm) because of the change of colours and intensity throughout the day. Boosts mood and energy and helps you focus and improves sleep which is very important for your health!

Bad electric lighting

• Most of the lights miss parts of the spectrum or have the wrong intensities of certain colours.

• They might have a weird yellow or bluish tint, and sometimes flicker, which you may not notice, but your eyes and brain do.

• Can cause eye strain, headaches, and make everything look kind of dull or unnatural.

• It can disrupt your circadian rhythm if you spend too much time during the day under electric lighting, which causes sleep problems and negatively affects your health and mood.

Why daylight is so important for your health

Since the beginning of human existence, our bodies have been completely programmed by daylight. The natural cycle of the sun rising and setting tells us when to wake up, when to be active, and when to rest. Daylight’s full spectrum of light helps keep our body clock, also known as the circadian rhythm, running smoothly.

But today, we spend more and more time indoors, under electric lighting that isn’t good enough. Many indoor lights don’t give us the full spectrum and intensity of light our bodies needs during daytime. And in the evenings, the light intensities are often much too high. That’s why electric lighting can mess with your sleep, mood, health, and energy.