Which flame will it give?

A fuel with a big share of carbon smokes when the air is short. You will find the share of carbon in some fuels, predict the flame of each, and find the sootiest. Then the program draws the shares.

The idea. Share of carbon $= \dfrac{12c}{12c + h} \times 100$. A saturated fuel, with $h = 2c + 2$, burns with a clean blue flame in plenty of air. An unsaturated one gives a yellow, sooty flame.

Your tasks.

1. In share, return the percentage of carbon by mass.
2. In flame, return "blue" for a saturated fuel and "yellow" otherwise.
3. Find sootiest, the fuel with the biggest share of carbon.