Up to twelve percent of children have diagnosed or undiagnosed auditory processing disorder, a condition that inhibits the brainâs ability to translate and process sounds.
Magnesium is sometimes used in flares and flashbulbs because it  burns with a bright white light.
What you probably mean is copper salts, which are used to color flames. There are two commonly used flammable copper salts and they produce different colors. Cupric chloride burns blue. Cupric sulphide burns green. There are other metal salts that burn other colors as well, for instance Potassium chloride burns purple.