Leukos means white or bright — appearing 25 times in the NT, predominantly in Revelation where it is the dominant color of the divine realm: white throne, white garments, white horse, white stone. In the ancient world, white was the color of purity, holiness, victory, and divine glory.
Revelation uses leukos systematically to describe eschatological realities: the Ancient of Days has white hair (1:14), the risen Christ rides a white horse (19:11), overcomers receive white garments and a white stone (2:17, 3:5), the martyrs wear white robes (6:11), and the final judgment occurs before a great white throne (20:11). This saturation of white in the last book of the Bible creates a chromatic theology of the age to come. On earth, Jesus's transfiguration clothing becomes leukos (Matthew 17:2) as a preview of resurrection glory. The disciples see two men in white at the ascension (Acts 1:10) and the women see a white-clad angel at the resurrection (Matthew 28:3) — white marking every transition between earthly and heavenly reality.