Yes, it could kill the Acropora. I've nursed a pale and slightly bleached colony back - and it takes time, patience, and good water conditions. Best is to figure out what is stressing the coral [light, chemistry, temp, etc] and to fix that ASAP ... then to slowly get it to gain color, move it up in the tank, slowly recover.
I would drop the temperature, and test Alkalinity.
How did you acclimate it to your light?