Depends on the dye quality. You’re getting a medium brown; if you use a semi-permanent dye, it will wash out. If you’re using permanent dyes (which can include box dyes, check the box to see if your box dye is permanent or semi-permanent), it should stay in your hair until you decide to change it or cut it. There are many other ways to have the lasting color you want without the upkeep, time, or energy! I recommend wigs. You can find wigs at your local beauty store, online, or custom-made by a small vendor. A wig might cost a lot more upfront, but it’s better than a hair color you may not want on your own hair. I recommend @melanin.minx_ on Instagram or their website; they have a great cause, are a small business, and you can get the exact color and length you want.