I am back to virgin hair, bleach or color?

I have not colored my hair in 3 years and it has grown out. I am going to give myself some highlights so it looks very natural. I didn't know if I should use bleach for this, or if I am able to just use color from the bottle. I was born a blonde, but over time my hair is now a light brown, like a level 6, so level 8 should be good for natural looking highlights? And, will I have to tone it if I don't use bleach?