Winsor & Newton’s Iridescent Medium for watercolours is a fantastic tool that can be used in two ways. Here we show three colours with this medium: Winsor Violet (Dioxadine), Lemon Yellow and Winsor Orange (Red Shade). First, you can see the colours as they are from the tube with only water, then with the medium mixed into the wet colour. The swatches with the medium are shimmery and catch the light, and the colour is also slightly lighter with the addition of the medium. The second way to use the medium is to paint it on top of dry watercolour, this layer of iridescent shimmer also catches the light but does not create a lighter tint of the original colour.