How does an onion seed turn into an onion?

Onions may be grown from seed (which are produced in a flower in the same way as most seeds are made) or, more commonly today, from sets started from seed the previous year. Onion sets are produced...

The part of the onion we eat is the root. The seeds are produced by flowers on top of the plant, just like most other plants.

An onion is a bulb that grows and produces seeds, which may be planted to grow more onions.

Not in the onion itself, but if an onion is left in the ground, it will send up a stalk from its center and a seed head will form at the top. You can sometimes see the start of this stalk inside...

Duh! Blue food coloring. if not then blue colored acid. p.s. just a guess.