If you're running just above 60F days 50 degree nights should be just fine, according to my research, and yes, it's probably where the purple is coming from, a 600w HID would add more illumination and solve your heating problem at the same time and as far as power costs, they're far more efficient than a 1000w, wouldn't jack up your bill much (I realize you may not have the 150.00 or so it costs to get a ballast, bulb and reflector kit) we were able to get by without getting a heater ourselves, I now turn off the intake fan at nightitme so as not to intake cold air when there's no light on to warm the air up and temps are up to about 65F during the day and 55F during the dark period.
:stylez rasta smoke: