Winsor & Newton Cotman Water Colours are a range of water colours that are made to our normal high quality standards but costs are kept to an economical level by replacing some of the more costly pigments with less expensive alternatives. Each colour has good transparency, excellent tinting strength and good working properties. Raw Sienna is a bright brown pigment. One of the oldest pigments, it can be found in prehistoric cave art. It is named after Siena, Italy where the pigment was sourced during the Renaissance.