Because surface brightness is low, such finishes contribute to a general impression of a dark space. High reflectance and light-colored surfaces reflect a large proportion of the light that strikes them, which produces a brighter interior with a more general diffusion of light. The next step in the lighting design process is to determine how much light is required for the activity that will take place in a space. In general, the light needed for visibility and perception increases as the size of details decreases, as contrast between details and their backgrounds is reduced, and as task reflectance is reduced. Recommended lighting levels are Published in the IFS Lighting Handbook 1981 Application Volume.
Color perception is yet another factor important to the appraisal and performance of a visual task.
Color characteristics of light can significantly alter a person's appearance. Incandescent light sources, which are rich in the red region of the spectrum, complement and flatter the complexion, imparting a ruddy or rosy hue to the skin. Choosing the light source follows easily once you decide on the color, quantity, and distribution of light for a space. At the counter of a gourmet food shop, for example, a diffuse distribution may be desired to provide a general brightness level and shadow-free illumination at the work surface, in a color that renders food appropriately. Placement and position of light sources depend to a considerable degree on the direction and distribution of the light decided upon.