Soil color is classified by
a. using a microscope
b. taking core samples
c. determining the proportion of minerals
d. using a color reference chart

Correct C). Determining the proportion of minerals

Soil color is known to be produced by the minerals in the soil and by the presence of the organic matter content in the soil.

Example: Yellow or red color of soil indicate that it has oxidized ferric iron oxides in it. The dark brown color of the soil shows the presence of high organic matter content.

The development of color in the soil is the result of biological and chemical weathering, especially the redox reaction.