Our office front doors use an electronic lock to enter and exit (but can also be opened using a key). To open the door from the inside, you need to press a giant unmarked red button to the right of the door frame, the type of button that's usually used as a kill switch on a factory floor. We also have 2 regular big flat light switches next to that giant button, one for the lights outside and one for all the lights on the first floor. The outside switch is marked "lights outside and garage" and the first floor switch is marked "general".
When our visiting customers first visit and leave, they see these 3 buttons and likely think "that red button is dangerous and I should not press that, that top switch seems to be for the light, that means that other switch is probably for the door". They press the switch, and all the lights on the first floor turn off. It doesn't mean we immediately go dark due to windows on both sides, but it usually means that someone needs to go turn the lights on again and tell the customer what the right button is.
The building is a rental so we cannot replace the button ourselves (the owners need to do it) or make the door function without the button. We have discussed it with the owners multiple times, but nothing seems to be done about it.
What steps can we undertake to clarify the intention of the button until it is replaced?
I'm seeing some mentions of etching a sign in the glass or otherwise altering the button itself. We're looking for something that we can do ourself and is reversible without residue in case the owner of the building (the landlord) does not like what we've done.