SetBackgroundOpacity

SetBackgroundOpacity(float value)

Sets the opacity of the background (how transparent it is). This should be a number from 0.0 (completely transparent) to 1.0 (completely opaque). Note that this function only changes the value stored by Quest, and it is necessary to call SetBackgroundColour to get Quest to update the UI. If you do not want to change the background colour, you can do this, for example:

SetBackgroundOpacity(0.5)
SetBackgroundColour(game.defaultbackground)