It is hard to imagine if either of Roma or Cold War would have been as sublime and deeply affecting a cinematic experience if not for their gorgeous high-contrast black-and-white cinematography.

A 2017 study, which surveyed some 1,000 millennials, found that less than 25 percent of them had watched a pre-1960s classic. Only 28 percent had seen Casablanca all the way through with 20 percent labelling such black-and-white films as 'boring'. Thirty percent of the millennials even admitted to having lied when asked if they had seen the classics, due to peer pressure.

Their resistance to black-and-white (B&W) films is understandable with colour having become the standard in the last 50 years. But filmmakers continue to embrace this seemingly dated format even if such films have been driven from the mainstream to the fringes of festival circuits. Two of the best movies to come out of last year's editions of Cannes and Venice film festivals happened to be monochrome masterpieces — the Palme D'Or-nominated Cold War and the Golden Lion-winning Roma. Both films are competing in the 2019 Academy Awards race for best foreign-language film, best picture, best director and best cinematography. In fact, Netflix's Spanish/Mixtec language drama Roma is also vying for best picture honours and could potentially make history, come Oscar night on 24 February.

Cold War and Roma have a lot more in common than the gorgeous high-contrast monochrome visuals, courtesy the Arri Alexas. Their similarities and differences shed light on why and how Pawel Pawlikowski and Alfonso Cuaron chose to shoot their films entirely in black-and-white.

Pawlikowski's continent-spanning quasi-musical romance and Cuaron's epic domestic drama are both set during different stages of the Cold War — the peak of Stalin's era and the Mexican Dirty War, respectively. Both are fictionalised cinematic memoirs that also function as an ode to the woman who raised them, their motherland and the movies.

Recounting his parents' tumultuous relationship, Pawlikowski's Cold War follows pianist-conductor Wiktor (Tomasz Kot) and singer-dancer Zula (Joanna Kulig), whose sweeping love affair takes them from one side of the Iron Curtain to the other and back — across Germany, France, Yugoslavia and Poland. In Roma, Cuaron reimagines his childhood growing up with his family in 1970s Mexico City through the eyes of his indigenous nanny and live-in housekeeper. And B&W cinematography helps evoke the required mood and memory in both these films while establishing an emotional distance from their subjects.

Shot in 4:3, Cold War draws our eyes to the characters' faces and expressions that fill up the entire frame — from the time Wiktor and Zula's eyes meet across crowded rooms to the times they struggle to stay together yet are impossible to separate. There's an intimacy and claustrophobic feel to the square frame, which always makes you wonder and worry about what misfortunes lie in its shadows and outside its borders.

Pawlikowski, reuniting with Ida cinematographer Lukasz Zal, emulates the soft textures of a grainy 35mm film using a digital setup. To top it all off, they give the film's classic Hollywood melodrama facade a French New Wave edge — with a few impulsively improvised handheld shots, plenty of cigarettes and a doomed romance that brings to mind films featuring the likes of Jean-Paul Belmondo and Anna Karina.

In contrast, Cuaron opts for a pristine, grainless aesthetic and plenty of natural lighting to enhance the sense of realism in Roma. He uses a digital 65mm format to choreograph, not direct, the most exquisite and expansive tracking shots — which stop just short of showing off — to convey the film's themes and the character's emotions. As the camera pans from one side to the other, Cuaron always maintains a distance between his protagonist, the maid Cleo (Yalitza Aparicio), and her environment.

For instance, when the whole family is watching a comedy show on TV, Cleo briefly sits down on the floor next to the sofa and quietly lets out a chuckle or two. Pepe (Marco Graf), the youngest of the family, puts his arm around her shoulder as if to say, "You're family too". But within a few seconds, the mother Sofía (Marina De Tavira) orders her to brew her husband a cup of chamomile tea. Cuaron observes through his lens how Cleo is a beloved part of the family but her role in the social hierarchy is still strictly defined by her race and class.

It is hard to imagine if either Roma or Cold War would have been as sublime and deeply affecting a cinematic experience if not for their monochromatic palettes.

As colour films became more and more prevalent after the 1960s, B&W cinematography has been almost completely phased out of practice and reduced to an aesthetic and/or budgetary choice. Contemporary filmmakers have usually ditched colour for black-and-white to pay homage to an influential cinematic genre or to evoke nostalgia for a bygone era.

Much like Pawlikowski and Cuaron, Noam Baumbach and Greta Gerwig mined their deeply personal experiences to write Frances Ha (2012) in the language of the cinema they grew up watching — from the New Wave dramas of Godard, Truffaut and Rohmer to the chatty comedies of Woody Allen. Baumbach depicts the quarter-life crisis of an unsuccessful, "undateable" dancer living in New York with the Raoul Coutard combo of static shots, long takes and the occasional exuberant camerawork. All this renders the film a simultaneously new and old quality, with a story set in a contemporary period but pastiching the aesthetic of another.

In the same year, Joss Whedon updated the setting of Shakespeare's Much Ado About Nothing to sunny Southern California but he draws out more of the classic comedy’s screwball elements in a clear tribute to the romcoms of the Golden Age of Hollywood. Fellow 'Golden Age Thinker' Michel Hazanavicius romanticised the magic of silent cinema in a modern tribute with The Artist (2011), which went on to become the first entirely black-and-white shot film to win the Oscar for Best Picture since the '60s.

However, B&W isn’t always used to evoke feelings of nostalgia or to pastiche classic genres, styles, characters and references. When Martin Scorsese chose to shoot Raging Bull in black-and-white, it helped him better capture the gritty violence and visceral experience of boxing — and it stood out from similar dramas that preceded it, like Fat City (1972), Hard Times (1975) and Rocky (1976).

Black-and-white cinematography lends a timeless, poetic allure to Alexander Payne's Nebraska (2013), a film with a visual palette as spartan as the lifestyles of the characters that inhabit its story. The vast expanse of plains, the long stretch of highways and the decaying small towns emphasise the gloom and isolation of the recession-hit Midwest. But despite all its bleakness, Payne never forgets to show us why he is the master of the tragicomedy, artfully toeing the line between levity and poignancy. Peter Bogdanovich had used the high-contrast imagery to similar effect in The Last Picture Show (1971) highlighting the economic and cultural decline of a small town, and in his timeless Depression-era tale, Paper Moon (1973).

A monochromatic aesthetic allows the characters, narrative and atmosphere to take shape within the play between light and shadow, the use of which helps create something unreal or more of a cinematic reality. In Ana Lily Amirpour's A Girl Walks Home Alone at Night (2014), an Iranian female vampire vigilante, cloaked in a chador, preys on wicked men to protect the women of a fictional ghost town from the violence of patriarchy. This setting begs for an otherworldly atmosphere and Amirpour uses black-and-white cinematography to also reflect the film’s narrative and underlying themes.

Often, the atmosphere is in itself a character in the film. Take the spellbinding work of Bela Tarr (spellbinding only for the most patient, passionate film lovers) for example. In Satantango (1994) and Werckmeister Harmonies (2000), the desolate outdoor settings are recontextualised to reflect the protagonist's consciousness. The monochrome-enhanced atmosphere becomes a visual extension of the characters' psychological landscapes, highlighting their dramatic internal conflicts and existential despair. Similarly, Eraserhead (1977) sees David Lynch use surreal imagery, building a decaying industrial landscape, to reflect the protagonist's state of mind.

B&W can also lend a documentary realism quality to a film. Steven Spielberg captures a world devoid of colour, joy and life in Schindler's List (1993) with Janusz Kaminski's stirring black-and-white images. Of course, Spielberg is not just interested in documenting the tragic events of the Holocaust, he also wants to dramatise them because it is after all a work of historical fiction and his vision. So, we often see him forsake the gritty documentary realism for a more deep-focus German Expressionist look, where he uses contrast more expressively than he might have otherwise.

In La Haine (1995), Mathieu Kassovitz drains the colour from the mythical Paris invented for the tourist and romanticist's imagination to show a city on the brink of a riot. It takes away the rose-coloured glasses and reveals a Paris that is more "La vie en noir et blanc," rather than the commodified "La vie en rose" — highlighting the harsh reality of its streets as the younger immigrant generations deal with mounting police brutality and racial tensions.

However, for many first-time filmmakers in the '80s and '90s, opting for B&W cinematography was an economic, rather than aesthetic, decision. Before all the fame and acclaim, Christopher Nolan (Following, 1998), Darren Aronofsky (Pi, 1998), Jim Jarmusch (Stranger Than Paradise, 1984; Down By Law, 1986; Dead Man, 1995) and Kevin Smith (Clerks, 1994) started off with self-financed, low-budget, black-and-white indie features.

B&W is hardly a new vogue in modern filmmaking and Roma and Cold War's Oscar nominations do not really herald a resurgence of sorts. But they can give it mainstream legitimacy in a way that The Artist couldn't. Cuaron and Pawlikowski showed there's still plenty of lessons to be learnt from the classics — and showcased B&W's potential even in the Aquaman-Thor:Ragnarok age of candy-coloured kaleidoscopes. Hopefully, more filmmakers and filmgoers alike understand the need to look back, to move cinema forward.