The exterior of Amy Exton’s Margate home is painted an innocuous shade of cream. From the outside, there’s no hint of what’s to come. But entering Exton’s house is like stepping into a psychedelic screensaver. Acidic yellows, pinks, blues and purples coat the floors, walls, stairs and ceilings. The effect is disorientating: 3D shapes are rendered 2D and, as the light changes, new colours emerge from every surface. Once your eyes have adjusted to the onslaught, you can start to take in the details: the cherubic lamp stands, porcelain leopards, kitsch side tables and plinths – the kind of objects that remain unsold at car boot sales. “How did this happen?” I ask.

“I don’t come from an interior design background,” says Exton, who studied fine art at Central Saint Martins. “I haven’t got all these rules to follow. I’m just kind of doing what I think looks good.” She cites Only Fools and Horses and the 1990s TV series Changing Rooms as the inspiration behind her “trashy aesthetic”. “Most things that I like would look terrible in most interiors, but the whole grey trend just isn’t for me.”

Exton’s house – her first, which she purchased two years ago – came to her in shades of “institutional brown”. The building is part of a late 19th-century complex, formerly Princess Mary’s Hospital, used as a tuberculosis sanatorium for children. The wards have been converted for residential use.

Cooking up a storm: block colours in the kitchen. Photograph: Jo Bridges/The Observer

Exton built sets for music and fashion shoots after graduating (the house is often rented out as a location), but her goal has always been to work in interiors. “I’m not very good at describing my work,” she admits. “I think that’s why I’ve enjoyed doing my first house so much. I can do what I want. I don’t have to answer to anyone. I’ve just gone for it.”

I spent a lot of time on one wall. I’ve got my technique down now. My style got madder and madder as I went along

And she really has. In the kitchen, she has painted a mural in starbursts of fluorescent pink, orange, blue and green. Slices of animal print are incorporated into the design. “I spent quite a lot of time on that wall,” she admits. “I’ve got my technique down now.” The animal print is handpainted. The rest of the design – which she makes up as she goes along – is the result of rolls of masking tape.

Behind the dining table is another mural, this time a tropical beach scene printed on vinyl. Exton has customised it with a wide border of animal print and diagonal stripes. Against one wall is a curved 1970s sofa in pink velvet – a vintage find which started life in the Ivy restaurant in London. “When I first found the house, I immediately went out and bought three sofas,” Exton recalls. “That was before I’d signed anything. I was just so excited to finally have my own place.”

‘The whole grey trend isn’t for me’: Amy Exton. Photograph: Jo Bridges/The Observer

The living room is on the first floor. In the right light, the purple of the ceiling reflects on to the coral-pink walls creating a two-tone effect that she compares to a tropical sunset. Her furniture is largely secondhand: the circular green dresser (which features on the cover of Be Bold, a new interiors book by Emily Henson) was found lurking incongruously on a country antiques website. Exton scours secondhand shops and car boot sales for plant stands and lamp bases that she then sprays in block colours. She is currently working on her own homeware range.

“My style got madder and madder as I went along,” she admits. In the upstairs bathroom she has installed a vintage pink suite. “This is one of the most photographed rooms in the house,” says Exton. “People just love coming in here and taking photos.” These “#bogshots” (selfies taken in the bathroom mirror and posted on Instagram) led to a mural commission from Radio Margate, an online station, performance space and café-bar.

On the top floor are two bedrooms. Exton’s is painted in a relatively safe shade of teal, with upcycled furniture adding blasts of pink and yellow. “The vintage wooden bed is probably the only thing in the house that hasn’t been painted,” she says. Next door is her housemate’s bedroom, currently off-limits because the colour isn’t quite right. “I wanted it purple, but it’s turned out lilac. It’s far too princessy,” says Exton. Luckily, it’s nothing a pot of paint and a reel of masking tape can’t fix.

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