Hello, I'm attempting to install a new head unit in my 99 lexus gs300, and I am having trouble identifying the wires, being that there is no harness that will work with this model, all have said is have to bypass the original amp..ok so I get that but now I have seen several articles online tell me different things on what color the constant battery, switch and ground wire should look like...ex..blue yellow for bat, gray for switch, and brown for ground...found all but brown ground wire...confused? Any help will do gents..thanks in advance