There are three settings to brennar used to light the underground cities of the Viroa: off, day, and night. During the "day", the hexagon tiles are lit with a pale green light. During the night the rhombus tiles are lit with a light blue glow. Due to being separated by the larger hexagon panels, the night setting takes the appearance of a starry sky.
The tiles of the brennar used to light mines and inside construction are normally either squares or triangles. Circles are avoided as being to elvish for dwarven tastes.