Derwent Artist Colorless Blender Pencil
If you want to create a subtle blend of colors then the Derwent Blender is the ideal accessory. The Blender pencil is a soft colorless pencil made from the binder used for colored pencils. It allows you to blend two or more colors together to create a new color. At the same time it physically mixes and smooths the colors so individual strokes and hard edges are softened.