On the exomoon Capu, spacefaring society was developed without electricity - so artificial light is produced using bioluminscent microorganisms, hence the different colors of the city of Calabaro.
Green and purple are streetlights and cars, while orange light spills out from brighter Lightwells and Lightpipes, which provide sun and a view to the nighttime sky to the city’s buried tunnels. Like most Capuan cities, much of Calabaro lies underground, to protect the city from fierce storms that buffet the land every dawn and evening. Long orange guide lights flank the city’s main rail line.
Planet Matroya, and its gaseous ring, the Mashveya, hang fixed in the sky to the east.