Help:Edit Environment
From TrainzOnline
The Environment window allows you to change various environmental settings in your route or session, such as the lighting conditions at different times of day.
There are three tabs in the Environment window, providing access to different types of options to adjust the environment.
Lighting Tab
The Lighting Tab provides access to adjust the colour and lighting options for different times of day.
Diurnal Cycle
The Diurnal Cycle button will start the clock running through the diurnal (day/night) cycle on your route, allowing you to quickly preview the world colours at different times of day.