Why do the roots of plants usually look white, rather than green?

The majority of leaves appear green because they contain chlorophyll, which is responsible for the leaves' ability to absorb sunlight and convert it into starch.

Chlorophyll is able to absorb sunlight and transform it into starch. However, since sunlight is made up of various colored lights (the frequencies of each light determine its color), chlorophyll is unable to absorb all of the sunlight. One of the frequencies that chlorophyll cannot absorb is green light, which is reflected into your eyes and causes most leaves to appear green.

The reason leaves are green and roots are white is because the roots are underground and do not receive light, which means they do not require chlorophyll.

Since plant roots are primarily used for absorption and storage rather than photosynthesis, they appear white because they lack chlorophyll, the green pigment that is responsible for photosynthesis and is mostly concentrated in leaves and stems.