Suki Waterhouse for Superga

Suki models her new range for Superga

Suki Waterhouse is undergoing something of a dramatic transformation when we speak on the phone. 'I'm just having my hair dyed brown,' she says nonchalantly. 'You've caught me at a very, very crazy time.'

By now, we've all seen Suki with her new chestnut brown 'do. And while we agree that going from a blonde to brunette is a bold move, this is probably one of the lesser (numerous, frequent) such 'crazy times' the 22-year-old model-come-actress has experienced.

Whether she's walking one of the biggest catwalk shows of fashion month, out partying with her close friends and fellow models Cara Delevingne and Georgia May Jagger, or filming the next big Hollywood movie (she just wrapped on the next movie in the Divergent franchise), Suki Waterhouse isn't exactly living a staid, run-of-the-mill existence.

And as well as her modelling and acting commitments – Suki's hair makeover is, in fact, 'for a film I'm about to start doing' – the 22-year-old has somehow found time to design a capsule range for Superga: the trainer brand loved by the likes of Alexa Chung, Rita Ora et al.

But wait. Hold on. How do you actually say it? 'I think it's Sup-er-guh,' Suki says. 'But you can say it how you like,' she kindly adds, making us feel slightly less ignorant for not being able to pronounce the Italian label properly.

Rather than just put her face to the collection – which comprises three flatform styles, a mid-top design as well as Superga's classic trainer in silver, dark green and burgundy – Suki has had a real hand in designing it. That was one of the reasons she got involved in the first place. 'They actually let you do the creative,' she says. 'They trust you and it's really lovely to have that trust. They must have been crazy to let me design, but they did.'

We'd say it was less a question of being crazy, and more the knowledge that Suki – with her Bardot-esque, eyelash-grazing fringe, love of nude lipstick and louche style – is a natural fit for the laid-back brand. And her love of all things Sixties is evident in the retro campaign. 'I just think it's the sexiest way of being,' she says. 'It's sexy when you want it to be sexy, but not in an overt way. It's cute as well. That era has something about it that's covered up, but also allows you to be free and sexy when you want to be.'

But, as Suki so sagely explains, having style is more than being able to put on a designer dress. 'I think being stylish is when you have confidence. At the end of the day who cares what you're really wearing – you could be wearing expensive stuff, you could be wearing cheap stuff, but what matters most is being confident about what you have on.'

It's a frame of mind that would have no doubt come in useful when Suki undertook her latest high profile modelling gig: leading the finale at the Burberry show at London Fashion Week earlier this month.

Come on then we say, what's it like taking part in such a mammoth show? 'F****** amazing,' Suki replies, not missing a beat.

'Last year I was absolutely terrified. Even when I've watched the show before I got this feeling of "whooaaa". But I was very relaxed this year. The fact that we were wearing sandals was great, and I knew what I was doing.'

So relaxed was Suki that she spent the run up to the show lying outside the venue on the grass, and only went in to get dressed 'about ten minutes before.'

Nevertheless, the model says she still felt like 'a midget ant leading a pack of giraffes' when she came down the runway 'because I'm so short compared to the others. But it felt incredible, it's really euphoric. I didn't really think anything of it and then when I did it I was like "this is really cool."'

It's not surprising then that Burberry is a stalwart in Suki's wardrobe, and that she has been wearing 'a lot of' the label (jealous, us?) recently. But with her diary packed with red carpet events and parties, Suki needs more than one go-to designer to dress her.

'Do you know who I really love? Emilia Wickstead. I love her,' Suki said of the other designers she likes to wear. 'I've worn quite a lot of her stuff and she just does the coolest shit. We both remembered the other day that I was in her first ever show when I was 16 – it was in a town hall.'

A town hall? It's safe to say Suki's modelling jobs sound slightly less provincial these days, but that doesn't mean she's always in couture. 'I prefer being casual because I feel I can be myself. I find that when I'm doing the red carpet it all goes out the window about how I'd dress if I was just going out with friends, which is annoying. I shouldn't really think like that. I feel way happier just dressing myself when it's not being documented.'

But, surely, it must be fun getting to put on a really nice frock on once in a while?. 'Oh of course it is,' Suki concedes. 'And you know what's fun? When you love what you're wearing. And it's only really happened to me a few times. I've loved a lot of what I've worn, but it's rare when you feel 100%. My best moment was the Met Ball. You never really know what you're going to get, as it's all quite last minute, but I was like "I love this dress".  And it was fun because of that.'

Otherwise, Suki's wardrobe currently consists of 'leopard print shoes, capes and silk shirts'. Oh and 'things with fringing', despite them being a 'toilet hazard' and an unfortunate incident at the Kate Moss Topshop launch a few months back which saw Suki's fringed dress get a bit, er, wet in the loo. 'It was bad. I told Chloe Green and she really didn't find it funny.'

Fashion aside, Suki's acting career is really gaining momentum. Her latest movie, Love, Rosie is out in October and she has just finished filming opposite Shailene Woodley  – 'one of the most incredible actresses' – in Insurgent.

So is this it for her now? 'It's one of those things that's totally unknown isn't it? It's like being at the bottom, it's completely new. It's quite fun being at the start of something again. For me, the best thing about these movies, because I'm not trained, is getting to watch and learn from these amazing people who are also my age. It's daunting when you think about it, but it's okay when you get there.'

Continued below...

By Olivia Marks