I commit every washing "sin" there is and never have a problem. Everything gets thrown in together: whites, lights, darks. Tide powder. Warm water wash, cold water rinse. Dryer on light setting. No dryer sheets. Been doing my laundry this way for over 20 years (since I moved out of my folks' house). Never had a problem.

Drives Dad nuts the 6 years he has lived with me (we each do our own laundry). He separates and does three small loads each week. I do ONE HUGE one and its over!