Munsell colour chart

Use a tape measure to allow the recording of depths and hence the thicknesses of the soil horizons in the profile. Colour is used to identify the different horizons within the profile. Standardized descriptions of colour can be obtained by the use of the Munsell Soil Colour Chart System (see Chapter 1). 

Color is important in all forms of potato products, boiled, baked, fried, and chipped. Where a limited number of broad classifications are used, as in some commercial processing situations, use is made of visual reference charts showing a limited range of colors. Such charts are available for French fiies (Munsell USDA Frozen French Fry Standard, X-Rite Right On Colour) and for potato chips (Colour Standards Reference Chart for Potato Chips, Snack Food Association). 

Chroma, which is a measure of the saturation of the colour, is expressed by the distance from the value axis. A typical plane in the Munsell chart is shown in Fig. 26.8, in which the hue 5Y (yellow) is illustrated in various values and graduations of chroma on the right of the central black/ white axis. On the left of the same axis the hue 5PB (purple-blue) is treated in the same manner. The individual colours are identified according to their positions and that represented by.the square marked X would be designated as 5Y8/4 the hue being followed by the value number and separated by a stroke from the chroma number. 

The Munsell chart and Ostwald s system are not all that might be desired because their construction and use are not free from subjective elements they have other limitations such as lack of permanency of the colour standards. In 1931 the Commission Internationale de I Eclairage, usually referred to as the C.I.E., recommended what is known as the C.I.E.. system for numerical specification of colour. The foundation on which the method was based was the colour triangle illustrated in Fig. 26.9. It is assumed that the corners of an equilateral triangle are illuminated by the... 

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