A walnut is a brown, rounded or oval-shaped nut with a smooth, thin skin that is often lighter in color than the rest of the nut. The nut is encased in a hard, brown shell that is difficult to crack. Texture The texture of a walnut is crunchy and firm on the outside, with a rich, creamy interior. Color The color of a walnut ranges from a light brown to a dark chocolate brown, with the shell often being a lighter color than the nut itself. Taste Walnuts have a rich, nutty flavor that is often described as earthy and slightly sweet. Nutrition Walnuts are a nutrient-rich food that is high in healthy fats, protein, and fiber. They are also a good source of antioxidants and other essential vitamins and minerals.