History comes alive when you can see the past in colour

‘The celluloid of a photograph holds them well,” wrote Ted Hughes. He was describing a wrinkled, faded image of six young men marching off to the First World War. When we see the past through images such as these, it really does look like another country. It can be hard to believe the people in them were real like us.

The first successful permanent photograph was created in 1826 in France, by inventor Joseph Nicéphore Niépce. He used a camera and a tin plate covered with bitumen of Judea, a photosensitive oil derivative that required about eight hours of exposure to sunlight to reveal the first nuances of the image. At the time, the possibility of photographs in full colour was a wild notion. Until the mid-20th century, crucial moments in the history of the world were registered solely in black and white.

Viewed today, the people in these images look distant, trapped behind the surface of the paper. In our vivid world it is difficult to truly grasp that they lived, breathed, made jokes, got bored – let alone that they shaped the world we live in now. Moving footage is even worse: captured with a slow frame rate, they move jerkily on today’s screens, as if they were marionettes.

But now we have the technology to apply colours to these images. Lord of the Rings director Peter Jackson has revealed that he is making a documentary about the First World War in which colour is restored to old footage from the Imperial War Museum. The effect is transformative: reports about the horrors of living in the trenches instantly make more sense once the colours of mud and blood are revealed. I know well the difference this can make, because colourising old photographs is my job.

It was three years ago that I decided to combine my Photoshop skills with my fascination for history. I used a portrait of an American Civil War soldier I found on the internet. When I started, I had no idea how many details I would have to take into account: the colours of uniforms, medals, skin tones, eye colours. I had to combine knowledge from physics, chemistry, cinema and traditional painting.

Yet I am not “painting over” history. It is not a careless or disrespectful process. I have to interrogate the historical evidence, understanding what a photographer has captured and investigating the circumstances that led to it.

Yes, it is artificial in some senses – a combination of research into things we can know for certain and guesswork about things we can’t. But that is the craft of every historian. I just happen to work in a visual medium.

I wasn’t prepared for the reaction my work would provoke. People tell me that, after seeing these images, they are able to look at history with new eyes. I am overwhelmed with requests, not only from museums and publishers but from people who want me to colour their parents’ or grandparents’ wedding photos and other pictures that have been sitting in the attic for years.

For me, it has been an incredible historical education. Seeing these moments in colour has completely changed my perspective. It connects us with the past in a visceral way, helping us realise that the people who lived there were just as real as us, and that they no more knew the outcome of the events they were caught up in than we know our own future. As Hughes put it: “That man’s not more alive whom you confront, and shake by the hand… than any of these six celluloid smiles are.” follow Marina Amaral on Twitter @marinamaral2; read more at telegraph.co.uk/opinion