Fireworks twinkle bright colors when reacts with oxygen

Fireworks twinkle bright colors when gunpowder and "stars" reacts with oxygen. (These stars hold fuel, an oxidizing agent, a binder and metal salts or metal oxides) [This information is found at https://www.livescience.com/32675-how-do-fireworks-get-their-colors.html if you'd like to go read more] :)

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.