Why does my propane gas barbecue put out an orange flame?

It is your regulator but don't worry, they don't cost too much. Regulators do wear out as the rubber gasket inside of them dry out. Also a few years back, some really poor quality regulators were on the market and were presenting a big problem but I think that issue had been solved.while you are working on it ,you should clean out your venturi tubes,valves,and orifices. They might have an obstruction like spider webs. Don't change the air shutters as they are preset at the factory.