Colour gives a ready clue to soil conditions and some important properties. It is due either to mineral or organic matter and mostly to both. Red, yellow or brown colors are usually related to the different degrees of oxidation, hydration and diffussion of iron oxides in the soil. dark colors of a soil are associated with one or a combination of several factors, including impeded drainage conditions, content and state of decomposition of organic matter, the presence of titaniferous magnetite etc.

Uniformity in nomenclature of colors is possible by comparing the soils with charts containing standard colours. One such chart is the Munsell Colour Chart. It consists of coloured chips arranged according to hue, value and chroma, the three simple variables that combine to give the colour. The hue refers to the dominant spectral colour, the value to relative lightness of colour and chroma to relative purity.

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