I'm aware of that, in a circuit, inductive loads need to be protected with a flyback diode because if the circuit gets open the magnetic field will collapse forcing a current flow in the opposite direction.
What I don't understand is that last part: opposite direction, let me explain:
Suppose now that the circuit opens. My understanding of what a current in the opposite direction should be is the blue line, and the actual current flow that must happen (otherwise the flyback diode needs to be inverted) is shown in red:
So, why is the actual current flow (red) described as in the opposite direction while it is going in the same direction as before?