I am not one to beat a dead horse, as I have nothing to gain by either convincing people, or not convincing people, rather there was a light indicator on board, but merely out of research and respect, I feel it is meaningful to all to present all data. Since my article was published, I have found two other sources that state such devices was aboard. (It seems very doubtful an article was, or would, have ever been written stating one was never installed

).
The first being 'The American Marine Engineer', Vol. 5, January, 1910, which states:
Each steamer will be divided into upward of 30 steel compartments separated by heavy bulkheads. An automatic device on the bridge will control all these heavy steel doors, making it possible for a single hand to close them all in almost an instant in case of danger. Each of these doors will be electrically connected with a chart on the bridge, where each door will be represented by a small electric light, and when on of these doors closes, the light will burn red, but while it remains open the disk will be quite dark. The officer on the bridge will thus be able to see at a glance whether or not all the compartments have been closed.
The next article being from the London, 'Electrical Engineer', Vol. 45, dated March 4th, 1910:
Electricity On Board Ships
Electricity is being used on the two huge White Star liners, the Olympic and Titanic, now fast approaching completion in Harland & Wolff's shipyard, Belfast. Lord Pirrie has taken a very keen and active part in the building of these two vessels, which will each have a gross tonnage of about 45,000, or an advance of some 12,000 tons upon any other Atlantic monster. The vessels are divided into 33 steel compartments, which are separated by heavy bulkheads. These doors can be closed by one operation from the bridge by means of an automatic device, and by the aid of coloured electric lights the officer on the bridge will be able to tell at a glance whether or not the doors are closed.
The first article talks of an ice rink being installed on the ship. Such fanciful thoughts, can lead to skeptical reviews. The last article is written in full. The only notable thing is the 33 steel compartment, which may at first be thought as not being correct. However, if one includes the 17 transverse watertight divisions, of Titanic's double bottom, than this would equal 33.
So again, I am merely posting these in respect of research. One can take them as they may.

Thanks to the University of Puget Sound Library for helping track down a copy of this last article... what an ordeal it was... lol.