Answer: No , a chemical change has not occured as it was easily reversed.
Step-by-step explanation:
Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substances. It can only be reversed with the help of a chemical reaction.
Physical change is defined as a change which leads to change in shape, size or state of the substance changes. No new substance is formed.It can be easily reversed.
As the hair colour was washed out and returned to its original brown colour, it was a physical change.