I'm having a similar issue. I'm working on a barn converted into a 4 bedroom self-catering holiday let. The 3 downstairs bedrooms have emergency exit doors leading to the outside with an emergency exit light unit above them - each light has a single bright green LED that is on all the time and a strip of white LEDs which I believe come on when the fire alarm is activated. At night the bedrooms glow green, all night, and it's horrendously bright in the smallest room which is only 2m x 3m big. I know that I wouldn't be able to sleep in a room like that, and if I was I would complain, ask to be moved or tape something over the light to hide it - this is not what we want for our paying guests.
Is the green LED simply an indication that the light unit is working? Or is it meant to be showing the location of the emergency exit in lieu of the alarm being triggered and the white LEDs coming on? Are we allowed to partially cover or dim the green LED so it is still visible but doesn't fill the whole room with horrible bright light?