The biggest problem with Jennifer Lawrence's new film is the lie it tells us about hair.

There’s a lot to say about  Jennifer Lawrence’s new spy thriller, Red Sparrow.

The fact that she plays a ballerina who is forced into using her sexuality as a weapon for the Russian government is a plot-line that could be seen as a tiny bit problematic.

But what has fans really god damn miffed has nothing to do with the character’s story arc and everything to do with her hair.

Specifically, one scene where, with help from a fellow spy, she dyes her naturally brunette hair to platinum blonde with nothing but a single application of an at-home dye kit.

And the friend doesn’t even wear gloves.

This whole thing is, frankly, outrageous.

Anyone who has gone through the intensive (or more often draw-out) process of lightening their hair from black or brown to icy blonde knows this is simply not possible – as a few fans have already pointed out on Twitter.

While recent breakthroughs in hair-dying technology like Olaplex have made it easier to go blonde and not have all your hair fall out in the process, it’s still a transformation that normally takes more than one trip to the salon.

If doing at home – which no hairdresser in their right mind recommends – Lawrence’s character Dominika Egorova would have ended up with orange hair at best after one application and need to repeat with enough time in between not to singe her hair off.

And there is no way her hair would be looking this good immediately after that…

To top it off, Dominika's next move is to dive into a pool - which, as some of us triggered with teenage flashbacks will know - is the fastest way to turn your hair a particularly disgusting shade of green.

If you are considering going for a dramatic switch to blonde like Lawrence's character, celebrity stylist Anthony Nader has this advice: do an intensive hair masque treatment a couple weeks before your salon appointment; consult with your hairdresser and get all the details beforehand and be realistic about the limitations of your hair.

And if you can't be bothered with all that, maybe just buy a wig like the Red Sparrow wardrobe team no doubt did for Ms Lawrence.