School of Specification – Specifying Colour

Dawn Scott, Senior Colour Designer & Inclusive Design Lead at Dulux, has produced a School of Specification module on specifying colour. Here she discusses colour theory and perception, as well as the benefits of using the Dulux colour notation system.

What is colour theory and why is it important in design?
Colour theory is the science and art of using colour intentionally. At its core, it explains how colours relate to one another on the colour wheel, how they interact visually, and how they influence human perception. In design, colour theory goes beyond aesthetics; it informs how we create mood, support functionality, and enhance user experience. Colour perception is deeply rooted in psychology – certain hues can calm or energise, aid wayfinding, or signal danger. For architects and specifiers, understanding these principles helps translate creative intent into practical, built outcomes that perform as well as they look.

How do we perceive colour?
Colour perception is shaped by our biology and the environment around us. The human visual system responds to light bouncing off surfaces, so factors like light source, surface texture, sheen level, and adjacent colours all influence what we see. A colour viewed under warm artificial light may appear completely different in cool daylight. Gloss finishes reflect more light and can appear darker than the same colour in matt. Even the size of the painted area can impact perception. Colour is never seen in isolation, it’s always contextual.

Understanding colour in context – not in isolation – is the key to getting it right”

What is the Dulux colour notation system and how does it help designers communicate colour accurately?
The Dulux colour notation system breaks down colour into three key properties:

Hue – the colour family
Light Reflectance Value (LRV) – a percentage that shows how much visible light a colour reflects
Chroma – the strength or saturation of the colour

For example, in the colour reference 30BB 08/263:

30BB indicates the Hue, so blue in this instance
08 is the LRV — meaning it reflects just 8 per cent of visible light
263 is the Chroma, placing it in the moderate saturation range on a scale from 0 to 999

LRV is especially important when designing inclusive spaces, as it helps ensure appropriate contrast between critical surfaces, such as floors and walls, or walls and doorframes, which can aid navigation, safety and compliance. Using a standardised colour notation makes it easier for architects, specifiers and contractors to communicate clearly and consistently.

How can colour be used to influence how a space feels or performs?
Colour has a powerful impact on spatial experience. Warm tones (reds, oranges) tend to feel more intimate and energising, while cool tones (blues, greens) feel calmer and more expansive. Darker colours can make walls appear closer or ceilings feel lower. Lighter tones can help open up smaller spaces. Colour zoning can be used for navigation, to define function, or to support neurodiverse needs. In healthcare and education settings, colour also contributes to emotional wellbeing, sensory regulation, and accessibility.

What practical advice would you give to architects and designers when selecting or specifying colour?
Always test colours in context – ideally on site, on the substrate, at the scale they will be used, and in the lighting conditions the space will experience (both natural and artificial). Be aware of the impact of lighting temperatures and the finish you will be using, as gloss, matt or textured coatings all reflect light differently. Fan decks and sample cards are useful tools, but they should be a starting point, not the final decision. Understanding colour in context – not in isolation – is the key to getting it right.