Light colours of the walls and ceilings reflect more light and make the room brighter. The lower portion of the walls and the floor should be darker. Artificial Illumination Overcrowded constructions hamper natural illumination. Buildings stand in the way of light. Apartment blocks pack as many dwellings together as possible.
Walls are shared and window spaces are reduced.
For reasons of privacy, windows are smaller and curtains are used. We have begun to air-condition and soundproof rooms, where there is no scope of an open window. Therefore we have to resort to artificial lighting even in during the day. Filament lamps and Fluorescent tubes are the two common options in household illumination. The filament lamp is usually in the shape of a bulb, producing yellowish light.