Virga is the term planetary geologists use for a coloured streak. 8 named features carry it, across 1 of the 14 mapped worlds, the largest being Shiwanni Virgae on Titan at 1,400 km.
Ranked across every mapped world, by catalogued diameter.
Naming themes are set per world, so one descriptor can draw on very different sources depending on where it sits. Across all 8 virgae, 8 categories appear.