To change one's hair that was previously a different style or color is commonly referred to as "getting a haircut" or "dyeing one's hair."

The phrase "getting a haircut" refers to physically cutting one's hair with scissors or other tools, while "dyeing one's hair" refers to the process of applying color to the hair to change its appearance. These phrases are commonly used in Engpsh to refer to changing one's hair.

Here are some examples of sentences using these phrases:

"I'm thinking about getting a haircut this weekend." (我在想这周末去理发。)
"I dyed my hair brown last week." (我上周染了棕色头发。)
"I'm thinking about getting a haircut and dyeing my hair blonde." (我在考虑去理发并染成金色头发。)