Years later, it’s still regarded as one of the all-time greats.

(Also: It looks great in a steamy sex scene.)

Why do you think that is?

Atonement

Credit: Alex Bailey/Focus Features

JACQUELINE DURRAN:It has unbelievably resonated.

But we didn’t know, really.

Most of the other costumes that Keira wore are not talked about at all.

ATONEMENT (2007)Keira Knightley

Alex Bailey/Focus Features

It has surprised me, and it’s surprised me that people still remember it.

Replicas have sold for insane amounts of money.

One went for more than $30,000.

ATONEMENT (2007)Keira Knightley

Alex Bailey/Focus Features

Crazy, isn’t it?

I think they sold one of ours actually.

They’re quite fragile.

Do you still have any?

No, I wish I had one!

But I don’t have any at all.

I don’t even think I have a piece of the fabric.

How did you and Joe initially envision the dress and work on finding the right one, together?

He knew that he wanted movement in the skirt.

He liked the idea of it being bare-backed.

He wanted it as showstopping as we could make it, and that it should be green.

The shade of green he wasn’t specific about.

So, you’re constantly thinking about taking away rather than adding.

It’s quite easy to find certain dresses that fit the fashion of that time for bare-backs.

Mostly, they weren’t quite as naked as the green dress.

I was changing everything to make a new dress.

I’m under no illusion that the dress that I’ve created isn’t a true 1934 dress.

It’s a combination of elements that has been made up by someone with a modern perspective.

But, everything within the dress is from the period; it’s just recombined in a modern way.

And then I chose the way that it’s wrapped around the hips.

I took that detail and re-interpreted it by finding the fabric around, which is probably more modern.

But it just fit the way I thought the silhouette should be.

How did you decide on and execute that specific, bright shade of green?

I bought this fabric and then dyed it to the green.

I needed it so you can make the duplicates and so you can experiment with the shape.

But for the color, we didn’t know what exact color we were going for.

We piled them up and we talked to Joe and we talked about the green.

And that was how we did it.

As to why that was the right color?

I don’t know.

I don’t really inquire why that’s the shade.

Well, broadly, green in film costumes is not an especially popular choice.

I’ve never done a bright green dress before or after!

I think sometimes you could go into very dark shades of green.

Another part of why I think this green dress resonates so much is that it’s a real collaboration.

The thing is, to make a dress that bold, everyone has to be committed to it.

It has to fit Keira in an iconic way.

Joe has to want it to have a function like that.

The real secret of the green dress is its function in the movie.

There’s a shot of her standing, smoking outsidethis side shotand the dress is quite well laid out.

Seamus shooting it in the full-length way and it being lit so beautifully is what sets it up.

Going intoAtonementand particularly that climactic scene, what conception did you have of the movie?

How did you think about it, thematically, in terms of the dress?

There’s a very strong feeling of heat and summer and dreamlike memory for the early stage.

It wasn’t particularly real; it was a memory.

We had both things running parallel with that.

There’s something, I think for everybody in their memory, about summertime as a child.

There’s a heightened sense of a remembered summer.

That was one of the things that I wanted to bring in, to 1934.

You’ve worked with Joe Wright throughout his directing career.

What do you like about designing for him as a director?

He’s very interested in color and he also has an instinctive feeling about color.

For instance, he really wanted Churchill’s dressing gown inDarkest Hourto be pink.

It wasn’t pink!

And he had a strong feeling thatBenedict Cumberbatchshould wear yellow inAtonement.

He has these color attachments to characters.

For me, that’s fantastic, because I want the costumes to contribute.

You worked on 2017’sBeauty and the Beast.

It was quite a different experience.

Finding the yellow wasn’t too difficult, actually.

We decided on one shade of yellow that we wanted.

That wasn’t too hard.

That was the difficult thing, and that’s what took us quite a long time.

It became less about me reinventing it and much more about me augmenting it.