I have red green white blue wires.

My
Old thermostat that I replaced I managed to get the unit to work with blue on y2. Red on rh. White on w and green on g. Problem I had was unit would kick off and right back on. Not sure if this was thermo when temp dropped/increased by degree or not.

New thermostat: honeywell wifi

I must have the blue to common and red to R for the unit to power up. Which only gives me white/green and that powers the fan and heater. Wired this way the ac does not operate only the fan. Any ideas? Also the unit is in a 3bed home. Gas heat. Elect. Ac