Pyromancy
Pyromancy (Greek pyr, fire) is the divination by observing fire: flames, color, sound, smoke, burned residues. Practice in many traditions: Zoroastrian (sacred fire), Vedic (Yajna), Greek (Apollo at Delphi, with the eternal sacred fire), shamanic.
Reading methods
Direction of flames, color (red/passion, blue/spirit), sound (crackle/conflict), shapes formed by smoke, burned residues (capnomantic variant).