If you didn’t know, compounds containing metal ions emit a certain wavelength of light when heated (this depends on the arrangement of electrons), and some emit a wavelength in the visible spectrum, producing colour. For example, copper can create a blue-green flame, and potassium can produce a lilac flame.
Has there been any attempts at artificial colouration of flame colours in certain products that could be used to indicate safety certification, temperature ratings of that specific appliance/equipment, make visible to what would otherwise be colourless flames, etc.?
I know something similar is done with certain gases, colourless and odourless gases that are dangerous (flammable, toxic, etc.) are given distinctive colours and/or smell.
People used to use a broom to detect hydrogen fires in (scientific) equipment. The fire normally being hard to see. I’m told that you would wave the broom around the equipment and when it burst into flame you’d found your fire.