A plug is correctly wired as follows:
Green/Yellow insulated core to the earth terminal (top)
Brown insulated core to the live terminal. The live terminal can be identified by the fuse. The fuse and the switch should always be connected to live as it is the live which supplies electrical energy to the device. If the fuse and switch were connected to neutral, the appliance could appear to be off, yet still be connected to live.
Blue insulated core to the neutral terminal.