The change is permanent (you can see the change even after you change the mission/terrain.) However, you can send an empty string to reset the lighting.
Description
Overrides currently used scene lighting. The operand is config that is placed as a string (not file). The changes may not be applied immediately, but can be forced by the call of simulWeatherSync.
Syntax
diag_setLightNew config
Parameters:
config: String - config in string form
Returns: Nothing
Examples
Example 1
diag_setLightNew "sunOrMoon = 1; diffuse[] = { 0, 0, 0, 0 }; diffuseCloud[] = { 0, 0, 0, 0 }; ambient[] = { 0, 0, 0, 0 }; ... ";