Forget colours, sometimes something could be live but only when a certain circuit or switch is on. Use a meter or just connect up one side of your new usb socket to earth and tap the other on to whatever you think is live. If the socket works it’s live.
As said previously you may find a feed that is associated with another circuit, which may only be live under certain conditions. So prior to checking for voltage make sure everything is off, except the main hab power circuit.