So, for these bottles, I started off mixing 1 packet of black flower paste with 2x 250g packets of dark green sugarpaste. It turned a sort of sludge colour!! But that was fine!
Once the bottles were dry, I mixed the TINIEST bit of Sugarflair claret colouring in with the glaze to give the final colour. That's because it was for red wine. If I'd been doing a champagne bottle, I wouldn't have used black flowerpaste, only dark green and I'd have used green colouring withe the glaze.