People experimented on their aquarium tank with a 3 days light out period to deal with Cyano or other algae outbreaks. They report that most corals have no problem staying 3 days with no lights.
That is only for 3 days and no record so far with one week or more?
As of now there is none though do not risk as they just say it is only good for 3 days. Algaes can live without light until 7 days. Remember that a coral which goes pale very quickly after making a lighting adjustment is normally from to much light. A coral that does it slowly can be from to little light, to high or low a temp or to low nutrients.