Only the Most Attentive Fans Know: Why the Avada Kedavra in That Death Scene Was Blue, Not Green

A spell meant to kill suddenly changes tone — revealing the true emotions of wizards, which are never directly spoken of in either the books or the films.
Harry Potter fans still discuss the scene in which Severus Snape kills Albus Dumbledore — doing so with an unexpected visual effect. His Avada Kedavra spell, instead of the familiar sinister green light, flares with a ghostly blue. But why?
Deadly Green and Strange Blue
In Rowling’s universe, Avada Kedavra is a terrifying, unstoppable curse. It requires a pure intent to kill. The green light symbolizes that merciless will. But what comes from Snape’s wand seems to say the opposite. The blue color is no accident.
As the story reveals, Dumbledore and Snape had secretly agreed on the 'execution'. Dumbledore was doomed because of a cursed ring and wanted to die quickly, so Voldemort wouldn’t triumph. Snape carries out the order, but does so reluctantly, with pain, on the edge of betrayal.
A Blue Flash as a Symbol
There’s a theory that the blue color reflects Snape’s inner conflict. Unlike wizards who use the forbidden curse with ease, he didn’t want to cause pain. The blue light is sorrow, regret — an act of mercy, not of rage. Fans and gamers offer other explanations: the blue may be a sign of sacrificial magic, like Lily Potter’s when she saved Harry. Or even a hint at Snape’s 'good' side, as an agent of the Phoenix rather than the Dark Lord.
Symbolism or Mistake
Some viewers saw it as a visual inconsistency, but over time, this detail has become a powerful topic of debate. And it seems Rowling left us a subtle clue: not all that appears evil truly is. Even a killing curse can be an act of love.