The Five Pure Lights are the most sublime essence-quality of the mahābhūta or classical elements ; namely: Space, Air, Water, Fire, Earth and constitute the Rainbow Body of Dzogchen. The Five Pure Lights are essentially the Five Wisdoms (Sanskrit: pañca-jñāna) and in their primoridal purity the unstainable substrate of the mindstream.
In the rite of the Ganachakra, all that is offered or within the chakra or mandala is augmented and purified by the Five Pure Lights of which it is constituted. There is understood to be a sanctification comparable to a transignification and/or transubstantiation which instead of adding anything new to the substances, returns them, but more essentially and fundamentally our cognition and perception of them, to their 'primordial purity' (Wylie: Ka Dag). It is important to emphasize that in the Dzogchen tradition the apprehender and that which is apprehended or stated differently, the perceiver and that which is perceived are a continuum and nondual so there is no dichotomy or separation.
Tenzin Wangyal holds that the Five Pure Lights become the Five Poisons if we remain deluded, or the Five Wisdoms and the Five Buddha Families if we recognize their purity.
The Five Pure Lights are also evident in the terma traditions of the Bardo Thodol where they are the 'coloured lights' of the bardo associated with the different families of deities. Refer also the colours associated with the different deities in the Five Dhyani Buddhas.