Fans of the Harry Potter film series have noticed a recurring ‘hidden theme’ in each of the opening credit sequences, and it makes complete sense when you consider the narrative as a whole

For many movie lovers, there is no cosier winter treat than settling in to binge the entire Harry Potter series – and there’s an interesting detail in every credit sequence that even the most diehard viewers may have missed.

As fans of the beloved children’s fantasy series will no doubt know, Harry Potter follows the adventures of a schoolboy wizard and his pals as they solve mysteries and repeatedly defeat the malevolent Lord Voldemort. With every magical school year that passes, the narrative becomes increasingly frightening and complex, ultimately culminating in a bloody battle between good and evil.

This stark shift in tone and move toward more adult themes is also reflected in each and every one of the opening credit sequences, and the ‘hidden theme’ is so very obvious once you notice it.

A number of viewers have clocked that the iconic Warner Bros. logo gradually darkens with each passing film, representing the lengthening shadows in the wizarding world as Voldermort regains his terrible powers. A screengrab of the shifting colour scheme was shared via the Australian parenting brand Kidspot’s Facebook page, with the following caption: “Viewers pointed out that the Warner Bros. logo in the opening scene darkens with each film. Fans speculate that as Voldemort grew stronger, the Wizarding World gradually got worse – the change in colour scheme symbolising this fear.”

For many, this small yet clever narrative detail proved surprising, while more seasoned movie nerds declared that it was ‘obvious’. One person commented: “Thought this was pretty common knowledge for any movie buff…” Another wrote: “Ah yeah cause each film gets darker in theme, was that not obvious to people?”

Interestingly, the colour palette used throughout the frames of the iconic franchise change dramatically as the story builds towards its epic conclusion. This is made especially evident in a visual representation created by MovieBarcode, a cinematography-focused website that compresses each frame of a film into one single image.

In the case of Harry Potter, the site compresses the frames from each of the movies into one picture, showing how the lighter browns and pastel hues of Harry’s early adventures at Hogwarts give way to much darker, moodier shades as his final showdown with Voldemort draws near.