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.
Spectrometry seems closest to what you’re asking for (studying composition through light frequencies), it can be done to a fire but you don’t usually resort to fire for testing substances unless it was already going to burn. For stuff like fuels you wouldn’t really do that except for calibration purposes (calculating what the mixture and temperature is and how to adjust it) and even that is so rare I haven’t heard of it in use (but some searches show dyes are in use for this although not through burning).