A house in the heart of leafy Kew is the unlikely setting for an unusual collection of souvenirs and some brave colours, discovers Cayte Williams
Catherine and Timothy Bates's home in the leafy London suburb of Kew is not what you would expect. Rather than housing Laura Ashley furnishings and David Wainright, it reminds one more of Maria Callas and Phileas Fogg.

She is a city high-flying opera buff; he is a measured design agent with a taste for understatement, but they both turn into shopaholics when they travel. They bought their house four years ago and have since decorated it from top to bottom. The result is a mixture of both personalities: dramatic and opulent but practical and easy to live with. Each room in the house is decorated in the colour of a semi-precious stone - lapis lazuli in the dining room, jasper in the hall - but what could be over- powering is comfortable and welcoming.

"Timothy tends to modify my wilder plans," explains Catherine. "I have this idea that I can fit five times as much furniture into a room as is humanly possible and he has to calm me down. He likes natural woods and effects where I like things painted. I wanted to paint the stripped-wood dresser in the kitchen but he talked me down from that one."

It's not just a question of taste. Timothy does actually sometimes tire of being stuck up a ladder. Catherine has the wonderful and original ideas (which she executes with aplomb); Timothy not only tempers them, but does most of the ground work. The most labour-intensive job was painting the hallway, something that Timothy got on with while Catherine was away on business.

"He just got on with it," she recalls, "and spent an entire three days painting this huge space." Timothy also showed perseverance by stripping all the banisters and fireplaces, but put his foot down over a textured ceiling in the living room. "I wanted to sponge it really lightly," says Catherine, "but Timothy just refused to spend any more time up a ladder."

However, it's Catherine who puts the most thought into the colour schemes. She's most proud of the living room, a green space that gives the impression of either being underwater or deep in a forest. "It always stays cool here even on a boiling hot day," she explains.

The walls are the colour of malachite and outside the wisteria almost covers the windows. "It is the room I always wanted," says Catherine. And when she says always, she means always. Even at the age of 11 she knew exactly how she wanted her house to look. "I knew I wanted it green," she recalls. "The original idea was that it was going to be Thirties-looking, but that has actually been modified. It's got lots of ethnic bits in it that we've picked up when we've been travelling. I know I'm a shopaholic, but Timothy is the same when we go on holiday. We have to take an empty suitcase with us to bring everything back in."

As it is, the living room is home to Turkish coffee pots, Hong Kong cricket cages, Zimbabwean wooden owls, Colombian masks and Mexican papier-mache skeletons. Mix that little lot with a Welsh harp and a Victorian donkey and you're asking for trouble. But somehow it all works, because the strong, clean shapes divide up the room. A dramatic chandelier (from Ikea, of all places) dominates the room, along with a triptych mirror they designed themselves and had made at Millennium in Barnes.

The dining room does not have the grandeur of the living room, but has all its charm. Catherine adores Italian style, and it becomes obvious as soon as you enter this room. "The colours are inspired by the crypt of St Francis of Assisi," she explains, "where the walls and ceiling were blue with gold stars all over the vault." Italian glasses and golden coffee cups sit on the dark wood table while, in the kitchen, most of the tableware is again from Italy.

The colour scheme here is canary yellow and cornflower blue, which pervades everything from the pelmets to the crockery and linen. On the neat table surfaces you'll find jars of squid-ink tagliatelle and exotic Italian oils. A cupboard is stuffed full of goodies from her travels, and on top sit oils and spices from around the world. This is actually a wardrobe that she has had fitted with larder shelves (it's much more practical), and which she refers to as her "delicatessen".

Catherine keeps most of her utensils and pans on display in pots or hangs them from the Lazy Susan in the middle of the room. "I hate having everything behind doors; it's as if you were ashamed of cooking," she explains. "You want all your utensils out where you can use them and I think they look wonderful in their own right."

The kitchen is by far the largest and brightest room in the house, and it leads on to the jewel-coloured hallway. Here sit a Regency-style bench and a very large gold and black mirror bought at Chiswick auction rooms. The sea-grass stairs lead up to the master bedroom, which is perhaps the most dramatic room in the house. Again, its inspiration comes from Catherine's childhood.

"The walls are tortoiseshell," she explains, "and the whole room came from a very old Hennessey cognac advertisement from the first Vogue I ever bought, which must have been when I was about 14. I remember that it looked as if you were viewing the amber colours of the cognac through the bottle, and it was set in a very Thirties room with purple curtains. I cut out the photographs and that's why I'm teaming purple with tortoiseshell. In fact I still have the photograph."

It might all look effortlessly simple, but blood, sweat and tears went into this room. "The walls went horribly wrong at first," explains Catherine. "I painted them bright yellow and splashed them with ochre, scarlet, dark red and dark brown. The idea was that an oil glaze would knock the colours back, but all I ended up with was some awful primary-coloured abstract painting.

"I covered the whole thing in mahogany varnaish and boot polish, whatever I thought would work. Eventually it had the desired effect." Which, after all, is the whole point.