evilproducer To change the lights all at once, select all the ones you wish to adjust and go to Edit—>Master Light. I window will open where you can include/ exclude light types, settings etc.
Is it just me, or does this cry out for a shortcut Key? Does anyone else think Carrara needs more shortcut keys?
File menu, Preferences, Keyboard Shortcuts, pick the “room” (Assembly is “3D View”), then pick the “categotry” (Master LIght is in Edit), then find the function (Master Light is just over halfway down). You can assign a shortcut to very nearly anything, but you’ll find that there are more functions available than there are key combinations to choose from