Eating one dark green and one orange vegetable each day is recommended because these vegetables are rich in essential nutrients such as vitamins A, C, and K, as well as fiber and antioxidants. Dark green vegetables like spinach, kale, and broccoli provide nutrients like iron and calcium, while orange vegetables like carrots, sweet potatoes, and butternut squash are high in beta-carotene, which is converted into vitamin A in the body. Including a variety of vegetables in your diet ensures that you receive a wide range of nutrients necessary for overall health and well-being.