Community term: Fire and Ice (F&I)
Marble Fade Karambit produces swirling red-and-blue patterns across the curved blade. Pattern indices that align the red on the playside (where the inspect camera looks) and the blue on the backside without muddy intermediate colour produce the "Fire and Ice" tier. Without the tight playside-red rule, the pattern becomes "Fake Fire and Ice" or just Marble Fade.