"Saturated hydrocarbons burn with a blue flame while unsaturated hydrocarbons burn with a sooty flame". Why?

(N/A) Saturated hydrocarbons contain a lower percentage of carbon and have a higher hydrogen-to-carbon ratio, which allows for complete combustion in the presence of sufficient oxygen, resulting in a clean blue flame.
In contrast, unsaturated hydrocarbons have a higher percentage of carbon and a lower hydrogen-to-carbon ratio.
Due to this, they do not undergo complete combustion even in the presence of sufficient oxygen, leading to the formation of unburnt carbon particles.
These unburnt carbon particles glow and make the flame sooty or yellow.