I believe it's solid white, but not 100% sure.
Your best option would be to get a light tester and see which wires work.
First though you should search for a wire diagram/color codes for your model.
All of my wires were on the left side/drivers side (USA) of the trunk.
On both sides of the trunk you should see 2 factory grounds. I connected my amp to the one on the right side of the trunk.
As long as the metal is bare where you connect it you should be good.