Dying Hair Brown Over Bleach blonde?

Okay so i bleached my hair a few days ago, now i've conditioned it the body is repaired, the ends are split (but once its all finished dyed I'm getting about half an inch off my hair anyway) I'm aiming to go a light brown. I added a pack dye of caramel which darkened the blonde from platinum to a middle blonde, my under layers were originally black and after bleaching went a copper colour. I dont mind as long as it all goes brown the underlayers can be a darker brown thats fine. So my question is to achive a light brown do I choose a hair colour that is slightly darker than the colour I want as the blonde will make it fade over the washes? And then later redye my hair frequently with the shade I want?