WIRING CODE HELP FOR THERMOSTAT

I am in an office and have an old Carrier programmable thermostat which no longer works. I purchased a Hunter 44660 thermostat to replace. My problem is that the wiring codes on the previous thermostat do not match up the codes on the new thermostat.
Codes and color for old (Carrier) thermostat

Black C

Yellow Y1/W2**

Green G

Orange R

Blue Y/Y2

Brown W/W1

There is also a white, red and pink wire that double back into the wall and I assume are not being used.

Codes an the Hunter thermostat

G W/B Y/O RC RC1 RH Y1

I'm guessing the G's and Y1 will be the same.

A/C is eletrical and heat is gas.

Thanks for your help.