GM has been using dexcool for over ten years. Unless someone changed it to the green coolant, it should be orange. They also sell coolant that is compatible with both green coolant and dexcool. I've used the dual use coolant with no problems.
Factory for that car is Dexcool though. Don't mix non-compatible coolant with dexcool, it will turn to sludge, block coolant passages, mess up the thermostat, destroy the water pump in the long run, and it's a pain in the butt to flush out.