Color contrast classes

degree of color distinction (color contrast) between colors within a soil are categorized as faint, distinct and prominent.
Discussion—Within this practice, these contrast classes are used to describe the degree of color distinction between two evidentiary soil samples, whereas the United States Department of Agriculture – National Resource Conservation Service – National Cooperative Soil Survey (NCSS) uses these contrast classes to describe color distinction within soil horizons. Faint color contrast is evident only on close examination. Distinct color contrast is readily seen but contrasts only moderately with the color to which it is compared. Prominent indicates colors which contrast strongly with the color to which it is compared; prominent colors are commonly the most obvious color feature of the section described. The NCSS thresholds between faint and distinct color contrast (1) are adapted as exclusion criteria in forensic comparisons of soil.