Those would be different things. Highlighting means partial notes of a different color added. "I would like [color] highlights. [Give details as to where and how.] Balayage is a particular type of highlighting technique. If you want your hair dyed completely, just say: I would like my hair dyed [color].

"I want to book an appointment with a hair salon to change my hair color. I'm not sure what to tell the hairdresser. Should I say, 'I want to get highlights, balayage, or dye my hair completely'?" Changes made: "hairsalon" -> "hair salon" (added a space between the words). "change my colour hair" -> "change my hair color" (revised for clarity). "idk" -> "I'm not sure" (replaced the abbreviation with a complete phrase). "highligh" -> "highlights" (corrected the spelling). "balayagr" -> "balayage" (corrected the spelling). "died" -> "dye" (corrected the spelling). Added a question to seek advice on what to say to the hairdresser.