It's possible the yellowing is a lack of proper air in the burn mix. That could be from some dirt or old food particles plugging the air ports/nozzles, or inadequate gas pressure from a leak at a valve; if it was just one burner that would lead me to check with mild soapy water the offending rotating valve, or any master valve if all the burners did it. The old Magic Chef stove in our Pace Arrow often needed new burner valve seals, etc., but no such problems have occurred with the Beaver's stove.
I've read commentary that fine dust in the air can cause yellow flame, by reducing pure air substrate to the mix, but that's unlikely in our coaches unless there's some reason the air inside is just inadequate. If there's an adjustable sleeve controlling burner air inlet, increasing that port size a bit may be all that's needed. The more air the bluer the flame, but there should be a blue flame core tip and slight yellow flickering noticeable.
My experience has been that low gas pressure due to ice crystals in the regulator, especially when outside temps drop, or just an older regulator on its last legs is as likely a culprit as anything, especially if all burners behave the same. That could also mean problems for the propane side of your fridge, perhaps not quite yet providing symptoms. Usually the result though is just inadequate gas pressure altogether.
I'd see that the tubes and nozzles are clean and any air inlets open enough. Barring that alleviating things, check for valve leaks behind each knob and any main valve. If you're uncomfortable messing with these things, consult a technician. Then consider having the regulator at the tank replaced; a look at the fridge nozzle's flame may confirm a bad regulator if it happens to be inconsistently yellow also, assuming it's nozzle was clean and the air inlet was previously adjusted right.
Joel
