The pigment responsible for the green color in plants is chlorophyll. This pigment plays a crucial role in the process of photosynthesis, allowing plants to absorb light energy, primarily from the sun. In doing so, chlorophyll facilitates the conversion of carbon dioxide and water into glucose and oxygen, essential for the plant's energy supply and growth. The presence of chlorophyll not only gives plants their characteristic green color but also underscores their importance as primary producers in ecosystems.