When it comes to colour design for exterior paints, the brightness of the colour used determines, among other things, how much plastered surfaces and thermal insulation are exposed to heating, natural temperature fluctuations and, as a result, possible damage. The values are of great importance to architects and other professions that deal with the design of building facades. The so-called light reflectance value (LRV) measures the brightness of a colour tone and indicates the amount of energy in the range of visible light that is reflected from a facade. The value for black corresponds to 0, that for white 100. Due to heating (day) and cooling (night), dark surfaces are exposed to higher thermal fluctuations than light surfaces.