Sienna is a warm, earthy color that ranges from reddish-brown to a more yellowish-brown hue. It is named after the city of Siena in Italy, where the natural clay used to create the pigment was originally found. Sienna is often used in art and design to evoke a sense of warmth and stability. There are two main types of sienna: Raw Sienna, which is a yellowish-brown, and Burnt Sienna, which is darker and more reddish due to being heated during processing. Both variations are popular in painting, especially in watercolor and oil paints, for their rich, natural tones.