Everybody knows that colours look significantly different at noon than at sunset. This is also true of colours used in the interior when they are viewed under different artificial lights.

Strong directional light that has been introduced to add interest to a space can produce glare and shadows which can cause confusion for the visually impaired.

Fluorescent lighting:
Fluorescent tubes commonly used as ceiling lighting on many corridors will:

• Emphasise colours containing blue significantly altering how we see a colour

• Produce pools of light and leave areas of deep shadow

• Cause glare when the fluorescent tubes are exposed, casting lighting shadows on surrounding spaces of walls and floor

Incandescent lighting:

• Emphasise colours containing red

 • Produce point sources of light

• Cause glare due to high luminous intensities

Point sources of light can be distracting for visually impaired people because they produce pools of light and shadows on internal surfaces. This can make the identification of visual clues difficult.

Poor colour rendering lamps can reduce the ability of observers to perceive colour contrasts.

Daylight:

Dependent upon time of day and location, daylight can significantly influence how we perceive a colour. Typically daylight gives a natural appearance to colours although time of day can alter our perception of a particular colour.

Early morning light is low in colour temperature and gives a cold, blue cast to all colours. Contrastingly, early evening light has a high colour temperature and provides a warm, yellow based colour glow.

Glare and directional light:

In many interiors there are lighting conditions which produce glare and shadows. Whilst this can add interest to a space, it may also create strong shadows which can appear as potential obstacles to somebody with limited vision.

Glare from strong directional light is also a problem ¬particularly where the sun's path tracks across a window. Large amounts of light on surfaces will cause contrast to be reduced and glare to increase. This is a particular problem where sunlight is reflected from shiny surfaces.