Hoe does Ariana Grande change her hair color so often?

Like one day she will have it light brown, almost blonde, then the next she will have it dark brown. I know she is not dying it anymore because she doesnt want to damage her hair again (and who would dye their hair every other day anyway), I dont see how it could be extensions because when she has it dark, it is all dark, its not highlights. And i know shes not wearing a full on wig either. Im just wondering how she is able to go from light to dark so often?