A "yellow flame" is a type of flame that emits a bright yellow color, often seen in candles, gas stoves, and campfires. This color is primarily due to the presence of tiny soot particles that glow when heated. Yellow flames indicate incomplete combustion, meaning that not all fuel is being burned efficiently, which can lead to the production of carbon monoxide. In contrast to a blue flame, which signifies complete combustion and higher efficiency, a yellow flame can produce more smoke and pollutants. Understanding the difference between these flames is important for safety and efficiency in various applications, such as cooking and heating with natural gas or propane.