There are a huge range of options and it would depend on the look and feel of what you want to achieve, your personal view on colour & boldness, what else is close by (to tie in with) and budget. A coloured glass, such as a citrine green or orange would look great. A very different style/look, but equally eye-catching would be some interesting patterned tiles such as the Patricia Urquiola collection from Surface Tiles in London (and elsewhere). My personal preference would be to opt for a white/grey marble such as a Calacatta D'oro which would be incredibly luxurious and bring in the white and soft greys as well as adding a hint of warm caramel. That is if budget allowed. Carrera marble is less costly but has a greyer background. It is always advisable to go and choose a slab of marble from the stone yard.

Hi Karen. I like the sound of grey. I'd go with something very light to brighten the space. Farrow and Balls slipper satin is a beautiful colour and would look lovely with grey units, perhaps shaded white. Little Greene Paint company also do lovely shades of grey. Perhaps Grouse on the walls and French Grey for the cupboards. A lighter floor and glass splash backs would also help to reflect the light and make it brighter. You could always add a bright accent colour on the splashbacks like orange or a mustard yellow. Good luck!

Hi Rosie, It's entirely down to personal preference and the style you're going for. A contrasting backsplash can create a nice focal point and add extra interest if you opt for plain tiles. Tiles are always classic though, and you could play with laying patterns and sizes to help make your kitchen feel wider and more spacious. http://www.toppstiles.co.uk/tprod47710/duck-egg-splashback-90.html 

I personally love tiles. I think they add interest. However I had to google Wow Fez tiles as I had no idea what they were! So they are Moroccan hand made style tiles and you are wanting plain white ones? Is that right? Are they like the ones in my second pic? If so, I think they are beautiful. I think metro/subway tiles are a bit boring unless they are an interesting colour. I would tile behind the cooker and up to the window sills. However some people have just an upstand in the same material as the worktop (picture below) and use a washable paint on the rest of the wall. It boils down to personal taste.