I recently had a gas insert installed, and so far I love it.. One question I have is getting the perfect flame color. The instructions aren't clear as to what color I want..? When it is warmed up to temp, I have mostly yellow, with a couple of blue spots. Do I adjust the air mixture so the blue just disapears, or do I want some blue.. I want this beauty being as efficient as it can possibly be. Thank you for any help you can provide...