四色, or Shishoku, is meditative relaxation game based on the mathematical concept of four colour theorem. Four colour theorem states that any map can be coloured in using only four colours, without any two bordering shapes sharing the same colour. In 四色 players colour in shapes as they elegantly shift between different shades. There is no winning, simply the joy of colour and the sounds of vaporwave music. As the title implies, this game can be played in both Japanese and English.