Hello FlykeysGirl, sorry to hear of your misfortune, but don't despair, you can turn things around.
Yes, several things which transpired in your system could result in what you are experiencing
Take a look at the link below. See post # 1 and read the 2nd, 3rd and 4th paragraghs. Also take a look at post # 3.
http://www.reefcentral.com/forums/s...intentional+premeditative+color+shifting+why+
Once you've installed a new heater, with time and stability, your polyps will color up. It won' happen over night, but a stable system will go a long way in restoring their colorartion. It could take up to 4 months as I have actually purchased bleached polyps and restored them to full health. A bleach corals isn't necessarily a dead coral, so there's hope and this is reversible. Can you share a pic of their current condition?
Good luck and I hope this helps.
Mooch