I have a an old thermostat that was damaged during a move so Ican't label the existing wires prior to removing it. It has 5 wires, white, red, black, blue and orange and I have bought a Honeywell programmable thermostat to replace it, model RTH4300B and I was wondering what colors match up to my new terminal? I also have central air.

Thanks

You will have to go to your air handler and out side unit to see what color wires will go to what terminalsThe terminals will be marked with a letter and should correspond to the thermostat letters.
It looks like some one may have substituted different color wires fo the normal yellow and green. Y & G