I miss my red hair :(

Okay, I'm naturally a brunette - well, to be more specific, I have warm, medium-chestnut hair. I was a redhead a few years ago, while my hair was still pretty short, so it wasn't a big deal to grow out. But now, my naturally-curly hair is down past my shoulders, almost halfway down my back. I really wanna go back to red but I want a fall-back for when it starts growing out, so I don't have brown roots poking all over the place.

Oh, also, I have natural blonde highlights - really light golden blonde. How do I avoid the highlights looking really brassy?

  maybe go to a light reddish brown.then you can still keep the brown and have the lovely red in it as well,without the roots being too drastic.