Winsor and Newton Gouache watercolors are supremely high quality and their Cerulean is no exception. Cerulean is rapidly becoming one of the most important colors on a watercolorists palette. It exists on the spectrum between primary blue and cyan, and the term itself may derive from the Latin (caelum) for "heavenly blue." Cerulean, as we know it today, was invented in 1805 and extensively marketed starting in 1860. It was widely popular due to its lack of green tint. Cerulean is excellent when mixing turquoises, and other blue-greens and is a very popular for painting skies in the American Southwest. It's soft, subtle hue is also popular for mixing with a variety of other colors and can be used to create a sense of movement in evening skies or water scenes.