Schala obviously has uber power if she's alive, Lavos has to keep draining her to sustain itself, and that she could rip a hole in time to send out Kid (who required further energy).
Also, if her hair was dyed, firstly, hair color just doesn't fade. Remember, the DBT is pretty much a stand still. Second, if her hair faded, her hair would have grown considerably, it did not.
It's just a case of Masato or whomever going "Kid looks hot blonde so lets make Schala blonde".