How Lighting Affects Colour

The other day, I was staring out of the window of my friend’s condo by Osborne, looking at the Legislative Building; it was close to sunset, and the scene was spectacular. Light shone off of the Golden Boy, the entire building bathed spectacularly in bronze and copper hues. Minutes later, I looked outside again, and the scene was completely different; it was dark outside, and the lights from the grounds cast the building in stark relief to the deep blues of dusk.

Lighting has a dramatic effect on colour, which is important to keep in mind when you’re printing off all manner of signage. The colours we see are based on a variety of different factors, the primary three being the frequencies of the light source, the frequencies an object absorbs and the frequencies our eyes can interpret. The third factor is incredibly important in specific cases, like when you’re printing for individuals with colour deficiencies (sometimes called colour blindness); for today, let’s look at the first two more in-depth.

Have you noticed that incandescent light bulbs glow with a warm, yellow colour? That’s because incandescent light actually emits more photons in the red and green wavelengths. Objects will absorb certain wavelengths of light, so when you see yellow, it’s because an object has absorbed most of the red, leaving only red and green. Under incandescent light, a yellow item will look more yellow; even a blue item might take on more yellow tones, because there are more red and green photons, and they won’t all be absorbed by the object.

Fluorescent lights, conversely, emit more light in the blue and green wavelengths; objects tend to look cooler in that kind of lighting. Halogen lights are almost all white, so they serve to bring out all the colour in an object; they tend to make everything look a bit brighter. Sunlight is a fickle mistress, as my experience looking at the Legislative Building shows; as it moves throughout the day, the colours it brings out can change rapidly.

When you’re creating a document to print, it’s a good idea to consider what lighting it’s going to fall under. If the documents will be displayed in a setting with controlled lighting - store signage and the like - print out a proof and test it under the lights to make sure it suits your needs. For printing in variable lighting, consider how changes in light will affect how the item looks; does the image still resonate in bright and low light?

Consulting with your print shop is a great way of learning about how lighting will affect the final product; your Winnipeg printers have years of experience looking at all kinds of documents in all kinds of light. Give them an idea of what kind of documents you’re printing and how they’ll be used, and they’ll tell you what to watch out for in terms of lighting effects!