I knew there was trouble ahead as soon as I saw footage of her first official outing after the wedding, to attend a garden party at Buckingham Palace for Prince Charles’s 70th birthday. Suddenly, Meghan Markle wasn’t just called a duchess: she looked like one too. She was wearing beige.

Beige, the colour of a quiet, mundane sort of evil. Beige, the colour that old white people use to disappear into. The colour that people in offices wear to blend into the walls so you don’t notice they actually left for their lunchbreak over three hours ago. The colour with which landlords paint over the cracks in rental flats and to which all rubble turns when buildings collapse into dust.

All right, so it hasn’t all been the same. The artist formerly known as Meghan has also recently worn dresses and hats and handbags in navy or black, with a touch of bottle green and even a wild moment of yellow. But the beige has crept in and made itself known as her base note.

Now you may think that a colour, in itself, is not capable of evil, but I have been a keen colour-watcher all my life and let me tell you, from wide research, that beige is a colour that harbours murderous intent to bore us all to death.

And then there’s its cousin, greige, which you can make by mixing together two other things: monotony and despair. All of these related shades spell out a disappointment in all the world’s flowers. They look like preened and perfected sick. And it is my belief that the palace has used the beige to take confident, opinionated, personality-owning Meghan away from us and turn her into a royal bot, like they always do.

Oh, I was a fool. I was wrong to hope but I truly did think – it’s embarrassing even to say it out loud – but the fact is, I really wanted to believe that she could marry into the royal family and still remain interesting.

Have you seen her recently? What is happening at the palace; what part of the machine has sucked in her soul?

Questioning, brainy – even political. I kidded myself that once her lily became gilded, her hair became a crown, and her house became a palace, that her job would not also become silence. Well, I was wrong – have you seen her recently? What is happening at the palace; what part of the machine has sucked in her soul?

Already, I feel nostalgic for the days when a headline about Markle would lead to a news story about an article that had emerged from her past life as a journalist, such as the piece she wrote so brilliantly about growing up mixed-race in Los Angeles; how her schoolteacher encouraged her to just call herself white because she could pass as white, but she didn’t want to pass. She wanted to honour her mother’s blackness and declare her own mixed identity. Before her wedding, you’d hear all this cool stuff about the time she wrote to a washing-up liquid manufacturer to complain about their sexist adverts on the telly and the manufacturer agreed with her and changed them. And she was 11-years-old at the time! Or her years spent acting in American dramas such as Suits.

But that was then.

In the two months since she became a duchess, the headlines have come to say things such as: “Meghan Markle now does her own make-up for royal public engagements”, presumably because she needs something to do because they have banned her from thinking and speaking. Now her full-time job is to dress like a wealthy old lady who has spent all her opinions in Harrods and kindly donated all her thoughts to charity. La Markle, previously, was someone you wanted to go for a drink with – the duchess is someone you’d be more likely to catch up with at a funeral. How did they transmogrify her with such alacrity? What powers, exactly, does the firm hold?

My favourite stories about Diana and Fergie were about their friendship and how they used to break out of the palace together to escape royal protocol. It seems to be a little-known fact that Fergie was a friend of Diana’s before meeting Prince Andrew, and so Diana introduced them, hoping to bring a friend into her cloistered royal life.

A year later, they were married and when Andrew held his stag do, Sarah and Diana snuck out to a nightclub dressed as policewomen for a laugh. There’s a photo of this happy event – it’s true!

The firm, as Diana herself so memorably labelled the royal family, did not look kindly upon any of these exhibitions of “personality” or “fun” and both women were punished and eventually shunned accordingly. But we all thought Harry and William had turned things around. We thought this marriage harboured something truly new. Perhaps it does – perhaps the Sussexes are working on some truly exciting charity project that we’re yet to hear about. Some groundbreaking project that will surprise us all. And maybe, just maybe, Meghan and her sister-in-law, Kate, will bust out the fancy-dress costumes for a night down the boozer.

Perhaps. Possibly. But I’m not convinced that Markle hasn’t already lost her sparkle, sucked up the pipes into the family factory in the manner of Augustus Gloop.

Still, there’s always a bright side – given the royal family’s usual traditions, we’ll only have to wait about eight years before she becomes a single mum with something to say and then this will all get interesting again.