Rachel is a 35 year old school teacher who has no man in her life and lives with her mother.
Each element give off a particular color when heated in a flame. (Some are colorless). Copper gives off a green flame but to do that there must be some copper compound IN the flame. (there are many other elements that also could be causing a green flame).
There are two main contributors to the color of a flame. The one that probably impacts the blue=hot most is Black-body radiation. The hotter the object's temperature, the bluer the emitted light is. Another major contribution is emission from electron transitions. It emits light in specific energies.