The game you want to create a mission for determines which version of Dromed you can use.
Maybe a history of Dark Engine tech could go here?
Thief 1 and Thief Gold use a monochrome light engine with 256 levels of brightness.
was there a version prior to 1.33?
Thief 2 introduced colored lighting, but reduced the bit-depth to just 5 bits per channel.
System Shock 2 is similar to Thief 2 but has a different style of game play.
New Dark is an unofficial modification of the Dark Engine that can play Thief 2, Thief Gold, and System Shock 2 missions. Missions built with this version of Dromed will not work in legacy games, but missions built with earlier versions of Thief 2, Thief Gold, and System Shock 2 can be edited with New Dark. The initial release of New Dark for Thief was 1.19 and for System Shock 2 was 2.40