Colour dynamics

Written in conjunction with Tom Porter, an acclaimed colour specialist and author of several books on architectural drawing and environmental colour.

The perception of colour is not a static experience, it is one that is in a constant state of flux. Subtle shifts and modifications of colour result from the effects of changes in:

When an area of colour is increased, such as from the size of a colour chip on a colour card to the size of a building, the resulting and radical increase in area means the same colour appears much darker than the small sample.

Similarly, change in the relationship of size and colour also operates over distance when, for example a building seen in the middle distance and therefore appearing smaller than when viewed close at hand, appears lighter in colour. However, as we move away from the building, its colour will appear progressively darker and less saturated. On moving further away from the building, the colour will begin to lighten and appear less colourful until, when viewed in the far distance, its colour will turn bluish – the result of a perceptual effect known as ‘atmospheric haze’. This is caused by the filtering effect of tiny air-borne particles in the atmosphere.

Light and colour are fundamental and indivisible characteristics which define architectural form and help shape our understanding of the built environment. The dynamic of light results from the movement of the sun across the sky, together with its angle of incidence to the Earth’s curvature. This causes the quality of its colour-rendering properties to constantly shift and change over time: thus, early morning light appears yellowish, then becomes bluish at midday and tends to redden at sunset.

Radically different colour-rendering properties can occur after dark when street lighting comes into effect. This is when the colour of a building can be distorted out of all recognition, such as under the orange glow from sodium lighting or the greenish glow from mercury lighting.

A further modification of light and colour is experienced through the incidence of reflected light. This is an effect that occurs when strong sunlight scatters and reflects colour from nearby surfaces to tint the existing colour of the object building. When it occurs, it appears as a shimmer of one colour over the surface of another. The resultant colour mixture on the eye causes a new colour expression which is usually unintended by the designer.

The surface of an object has an influence on its appearance in terms of reflecting and scattering light. Surfaces can be designed to achieve a certain effect, which may vary between subtle and stark. The visual effect of texture depends upon the intensity and direction of light and the position of the viewer. In general, the textures seen in cladding are only distinguishable at close range, such as within 3 metres. But a change in texture can be the difference between a matt or sparkly appearance, a intended or unintended finish. Textures are used to ensure the surface matches the physical and functional requirements of the application.