Harry Potter fans have just found a secret theme to the series' opening credits

Anybody of a certain age will remember binge-watching the eight Harry Potter movies – but fans are still discovering Easter eggs in the films.

One of those is something the producers slipped into the iconic Warner Bros opening credits, and it’s glaringly obvious once you’ve noticed it.

With each new movie, it turns out the Warner Bros logo becomes darker and darker, until, by the last film, it is a threatening, inky black.

The changes reflect the tone of the stories with each instalment. The first one, Harry Potter and the Philosoper’s Stone, is a family-friendly classic.

It’s certainly a far cry from the spooky – and sometimes downright terrifying – final films, Harry Potter and the Deathly Hallows parts one and two.

In the opening credits to the final movie, even the metallic Warner Bros logo is growing rusty, and the material is starting to peel off.

As the evil wizard Voldemort grew stronger with each film, the wizarding world got more dangerous, and Daniel Radcliffe’s character’s plight became more and more dangerous.

Viewers couldn’t escape the fact that, for young Potter fans, it somehow reflected how life gets more serious as we get older.

One person wrote on social media: “It's like my life. First years are the best, but the older I get, the darker life gets.”

Another person said: “Did they forget that it’s a children’s movie?”

A third person demanded answers. They said: “There needs to be more info about this. Was this planned? It starts getting dark literally on the second WB sign.”

And a fourth, slightly happier, commenter, added: “This just made me so happy I need to go on another Harry Potter marathon.”

Each to their own, it seems.

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