Aerial perspective, or atmospheric perspective, deals with the greater or lesser definition which the outlines of objects acquire according to their distance, the changes which the colours undergo with distance due to the absorption of light in the atmosphere, etc., see Perspective.
As the distance from the viewer increases, objects appear paler and their hue shifts to the background colour, usually bluish, or brownish in fog, dust and smog, or reddish at sunrise or sunset. Leonardo da Vinci recognized and used aerial perspective to create an illusion of depth in his paintings by making distant objects paler, less detailed, and more bluish than less distant objects.
In the same way, aerial perspective can be used in modelling. Depending on the scale of the model to be painted, the original colour is tinted to a greater or lesser extent with white, yellow or ochre, i.e. desaturated, and muted with black or the relevant complementary colour. Steve Zaloga recommends tinting the paint used on a 1:72 scale model approximately 15 to 17 %1. Jim Gordon, author of Weathering Small Scale AFVs, tints his models with 10–30 % white.
Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909
Zaloga, Steve: Olive Drab (Military Modelling, 2002)↩