The royal family missed an opportunity with Kate Middleton's BAFTAs appearance.

Kate Middleton is used to standing out.

She’s the darling of the royal family. The regular, middle-class Briton who scaled the walls of Buckingham Palace. The woman whose sartorial influence is so powerful, the term “the Kate Middleton effect” was coined in her honour.

But today, at the 71st annual British Academy of Film and Television Awards (BAFTAs), the mother-of-two stood out for the wrong reasons.

All women attending the prestigious ceremony in London had received a letter asking them to wear black to support the #MeToo and Time’s Up movements.

Just like at the Golden Globes on January 7, the red carpet transformed into a sea of black. The message from the British entertainment industry was loud and clear: The grimy culture that allowed sexual harassment and assault to fester would no longer be tolerated.

This is more than just a token gesture. Last month’s red carpet protest had a huge impact on raising awareness and steering resources in the right direction.

And then the Duchess of Cambridge, 36, stepped out of her car. Her gown was impossible to miss.

It was an unmistakable shade of green.

We had, of course, been bracing for this. Ever since it was announced on February 8 that Kate would join her husband, who is the BAFTA president, at British film's night of nights, there was speculation she would be forced to defy the protest.

Official protocol dictates that members of the royal family should "remain strictly neutral with respect to political matters". They are also encouraged not to wear black unless they are attending a funeral.

Nonetheless, we held onto a sliver of hope that this was a cause for which she would be permitted to break tradition. At last year's event she wore a black dress with only sprinklings of colour.

And yet, she went for green.

It's been suggested that by wearing a dark green together with a black belt and clutch, she was hinting at her support for Time's Up. (On this, Kensington Palace has declined to comment.)

But "subtle messages" are not enough. The reaction has not been positive.

Kate Middleton defies BAFTAs black dress code for green Jenny Packham gown

God forbid the royals support what is right, they are even letting a yank into the family

— sue (@Feisty_Female) February 18, 2018

Honestly a bit confused about Kate Middleton wearing green, how is supporting victims of sexual assault and harassment a political stance and therefore why would it contravene royal protocol? #BAFTAs

— Josephine Atkinson (@Jos_Atk) February 18, 2018

That awkward moment when Kate Middleton isn’t wearing black #BAFTAs

— Sophie Haynes???? (@SophieeHaynes) February 18, 2018

Kate Middleton wears green and not black for #TimesUp
monarchy is so out dated

— Claire (@_ClaireMccord) February 18, 2018

I want to be clear on one thing. This is not a criticism of Kate. Attacking another woman would go against everything that Time's Up is about. I understand fully that she is bound by the rules thrust on her by the royal family.

This is about the royal family's failure to keep up.

Kate is a fierce backer of many social movements. She helped create the Heads Together mental health campaign, and she has done work to help fight perinatal depression and drug addiction. So, you can safely assume that given the chance, she would be lending her voice to Time's Up. Wanting a world free of sexual harassment is not a far cry from such important causes.

Watch the Duke and Duchess of Cambridge arrive on the BAFTA Awards red carpet in the video below.

Time's Up and #MeToo might indeed be political movements, but not in the classic sense. This isn't akin to debating health resourcing, welfare payments or education funding, where 'right' and 'wrong' depend entirely on what side of the political spectrum you stand.

When it comes to gender equality and sexual misconduct, there is a very clear 'right' and 'wrong'.

Quite simply, Time's Up is a cause that has universal support because we can all agree: nobody should have to be assaulted or harassed.

The idea that showing support for victims of abuse is a "political statement" is absurd.

Rather, by not taking part in the BAFTAs red carpet protest, Kate made a statement that stood out even more: that the royal family is a gravely outdated institution.

She should have been allowed to join the right side of history. Instead she was made to look like fool, through no fault of her own.

You can follow Sophie Aubrey on Twitter.

LISTEN: The Mamamia Out Loud team explain what the Time's Up movement actually does.