Read the report now, interesting reading. What strikes me is this:
The trial concluded that, while a white lamp could
be seen at a range of about 1 nm, a red or green filter
would make the lamp impossible to detect
I once flew into Malaga when the tower controllers there tested their lamps (and informed everyone on frequency about it). Both red and green were most definitely visible from about 5 miles out. Would perhaps not have made a difference in this case, but why withdraw the lamps from several airports (according to the report) ?