1) Red textboxes mean you really shouldn't edit them, because the room has no FX1 for itself.  Yellow means it has some, but these aren't the value you want (implementing later).  White means you're good to go.
2) "Select" . . . 0000 = uses FX1 . . . FFFF = no FX1 for the room . . . Others = wrong values at the current time.
3) Changes to the FX1 pointer (upper-right) only take affect after saving the room.