The current from the battery always flows from the positive terminal of the battery to the negative terminal of the battery.
If we connect a red coloured wire to the positive terminal of the battery and black coloured wire to the negative terminal of the battery, and then reverses the wire to their respective terminals, then there is no change in the direction of flow of current. It does not matter that which wire is connected to the particular terminal. The current always flow from positive to negative terminal of the battery outside the battery.
