Shadow Paint

Shadow paint is an item added in the 1.2 update. To obtain paint, it must first be bought from the Painter NPC. It is used to paint walls or blocks. This is done by clicking on the desired block with either a Paintbrush or a Paint Roller while the paint is in your inventory. The paint will be consumed in the process.

Shadow paint casts a very deep shadow on the block its used on, bright lights can barely reveal the type of block that has been painted