Soil color is one of the most diagnostic features of a stratigraphic layer, and the munsellColor field captures it in the standardized Munsell system — a notation like "10YR 4/3" that names hue, value, and chroma. Recording color in Munsell terms rather than plain words makes descriptions objective and comparable between recorders, units, and sites. The field is optional, since color may not always be taken, but it is standard practice. It sits alongside soilTexture and compactness to build a full soil description for the layer.
Technical section
Data model, API, and internals — visible to developers.