How to dye over turquoise?

So... I messed up. A while ago I tried a semi-permanent ashy brown over brown that had gone brassy and it stuck too much to my bleach damaged hair and turned out too dark in some places. I've been trying to fade it but eventually caved and bought a pack of Colour B4 since I have had good results with it in the past. I now have dark blonde hair with turquoise streaks.

I'm keeping my fingers crossed it will re-oxidise enough to cover it, but I think I need to dye over it tomorrow. I have to use a box dye as I don't have time to order online - I just can't walk around like this...

I know any medium/dark brown would probably do, but I really don't want to go too dark, and I know my hair soaks up dye when damaged. I know that orange/red will counteract blue/green, so I was thinking a coppery colour that isn't too bright. I don't want my hair to be red-red, just a warm light brown/dark blonde copper thing. I looked online and found Schwarzkopf Pure Color in 7.57 True Toffee which looks good, but I really have no idea what could fix this, so I'm open for suggestions.

Anyone covered up turquoise with box dye before? What did you use and how did it turn out?