Colour Cube
A Colourcube resource is used by both the EnvironmentSettings and PostFX to change the colour and tone of the world.
The colourcube is a 1024x32 [1] which is usually colour corrected to give a different art style to the game at a given time (i.e the red filter when wrecking a vehicle in versions 1.0-1.3 of Burnout Paradise)
Some time after the February 22, 2007 build of Paradise, colourcubes were added to the Environmentsettings folder and were used specifically to give the game a unique art style.
In the 1.4 update to Burnout Paradise, the colourcube was changed to a standard RGB CLUT, possibly due to the extended timecycle conflicting with the colourcube's art style.