Mars Lumograph Colour Aquarell are watercolor pencils from STAEDTLER. You color with them first. Then you go over the color with water, and it melts like paint. The leads dissolve easily in water and leave few marks. They hold a lot of pigment and resist breaking. Each lead is 3.6 mm thick.
The range has 120 colors. Sets come in 12, 24, 60 and 120 colors, and every color is also sold on its own. Each color has a published lightfastness rating.
Use a water brush to blend the color or spread it out. You can also skip the water and use them like regular colored pencils.