Hello, I have just finished DIY-ing my small white kitchen, but your lovely kitchen is large enough for you to play with colour. But also can be costly if you do not like what you have chosen. There is so much out there, it can be taunting. Take your time as there is no hurry (unless you have self imposed one) as the kitchen seasons change and you must have this and that NOW! Looking at your pictures you seem to like yellow, orange and there seems to be some greens (Ornaments, pots and plates) plus some woods. Start with those colours to compliment and pull it all together. What are your favourite colours, flowers? Or a favourite piece of fabric, pattern, design style or era ? Start with things you like then eliminate. If you are not sure as depending on your kitchen orientation the colours will change with the light, also due to shelving, cupboards a lot of shadows will darken the colour. I could experiment with some colour pots or and get some made up of a colour you like or take the ornament to a DIY store. They can make up the colour for a couple of pounds. Paint some paper A4 or bigger with whatever colour you think will work. If you think glass splashbacks put a piece of glass over it (an picture frame glass will do, if you do not have one they are pennies at a charity shop and you can donate it back), hang them at different places in the kitchen at different times of the day with lights on and off. If tiles, get samples. Do the same thing. If you cannot return the tile samples use as place mats or to protect your kitchen surface. If there is a wall paper that you think will give your kitchen a kick. You can use it and then seal it by putting clear acrylic or glass over it, if going for clear glass check if it has a green hue or pure clear, a green hue will change the colour underneath it. And the inside of your shelves can be a colour or pattern too. If you have children or grandchildren, you can now with laser technology get templates and photos of them and or their art work on paper an seal it. I hope this helps to do what you want and not influenced by "designer fashion". Have fun!

I normally have a real dislike of glass splashbacks, kitchens are full of lots of lines and generally a lack of texture but I actually like these with everything else in the room. I would choose the neutral one though rather than have the glass standout

Kath, the joints can look very neat and tidy when you use a jointing strip - https://alusplash.com/gb/edge-profiles/ What we tend to do with this type of splashback, or a glass one for that matter, is to have joints on either side of the hob. By the way, it could also be seen as a design opportunity by introducing a second colour between the two main sections.

If you include a 100mm upstand you will still have a gap if its 660mm and the alusplash is only 610mm wide. You could make it look deliberate by stopping under the units and having the gap of 50mm. I wouldn't do the upstand and then the alusplash its not sleek. If you do the alusplash start at the worktop and have the gap above. That could be the starting point for the shelf. Metro tiles are fussy to clean and unless white on white can look very busy. Zellige tiles are stunning but for that square meterage probably eye wateringly expensive. I would do a serious houzz search of what you are planning in photos, save lots to ideabooks and then see which style appeals to you the most to help you decide. If you have the upstand I wouldn't do any splashback above it. It looks great with only a good wallcolour.