bell-box wiring problems?

I have removed the old advantage zx6 panel and replaced it with an optima mini leaving the connection to the original bell box till last,
everything seems to be working fine but the new panel calls for only 5 wires to be connected
red
black
green
white
yellow
unfortunately i have a blue wire left from the old installation can any einstein tell me what to do with it. no ribald remarks please.