If i use loreal super blonde to lighten my hair, how can i touch up my roots without buying a whole other box?

I'm planning to lighten my hair to blonde, i dyed it brown a while ago, and my new color will be lighter than my natural blonde. I'm planning to do a very light color over the summer and a slightly darker one for fall but i dont want to buy a whole new box of loreal super blonde halfway through the summer just to do an inch of roots. is there any equivalent the pre-lightener made only for root touchups?If i use loreal super blonde to lighten my hair, how can i touch up my roots without buying a whole other box?
Use clairol nice 'n easy root touch up they have many blonde shades including natural light ash blonde and natural light neutral blonde so i'm sure you will be spoiled for choice!








Good luck, hope i helped!