If I put pink in my highlighted blonde hair will the pink eventually run and mix with my blonde?

I have medium lenght hair and I've just done my Junior Certificate exams(i'm irish)And when the results come out my mam is gonna give me money so I wanted to change my hair(in a salon).

My hair is naturally brown but I have it highlighted blonde.I want to maybe put pink chunks or pink streaks or just pink underneath my fringe or something but i'm worried that in time,when its washed the pink will fade and mix in with the blonde and won't wash out completely and I can imagine this will not look very UGLY lol.But i'm really keen on the idea.So I want to make sure it will turn out alright and as i'm 15 I haven't got the money to be getting my hair toned or anything if the pink goes wrong.

If I put pink in my highlighted blonde hair will the pink eventually run and mix with my blonde?

well..i have natural blonde hair and i did it with the home stuff and it didnt run to the rest of my hair it just faded and it looked bad. and i know ppl who got it professionally done and it still faded and didnt look that great. i say get the fake hair clips. i know ppl with those and i never knew it!! and if you really dont like the look you just take em out..they look soo real