Hooking up an rth2300 thermostat to replace a hunter 44402 thermostat, have red, yellow, brown and black wire out of wall how do I hook up

Did you tag each color wire ,as to what they were hooked to (which post) on the hunter tstat? Brown and black aren`t standard colors for tstat wire,so we need to know what they are hooked to, may help to look in furnace and tell us what they are connected to on that end