Sakura XBR-6SA 6-Piece Koi Coloring Brush Pen Set, Gray Koi coloring brush pen set These pens perform similar to an artist brush The durable tip will quickly spring back to its original shape The odorless, water-based solvent facilitates smooth blending and layering of colors Set consists of cool gray, dark warm gray, warm gray, light warm gray, dark cool gray and light cool gray colors