IMO you should not reattach those two cords and if they were previously connected, and the blue/brown/green is the clock side, I would say it was done wrong.
One side has a brown/blue/green with yellow stripe and the other only has a black and a white (that I can see). The blue/brown and black/white can be matched up correctly, but the green and yellow is a ground and if that is the clock side of the wiring it should be attached to a ground and not left unconnected.
Personally, if this is line voltage (and both wires' color coding seems to indicate it is) I would replace the entire cord with a correct cord. As this is a cord and could be subject to stress a simple twist is not enough, perhaps a lineman's splice would be. If not replacing the cord, I would also use something more durable than tape like heat shrink tubing ... you can get butt-splice connectors with heat shrink ends.
As a personal opinion, regardless of if one can/is allowed to make a connection between two line voltage wires in an exposed cord I will always prefer the connections to be enclosed and any stress to be controlled by something other than the wire connection; such as an electrical box with clamps in the cord, making the connect to the house wiring inside a wall box, or having the connection inside the clock enclosure.
Edit: It looks like the brown/blue can actually be either AC or DC, but the white/black should be AC assuming it was done correctly in the first place.
