Hi. I disagree with the previous comment (sorry!). Wall colour can be easily changed whenever you like but floors are a much bigger challenge and need careful consideration. I am a fan of light floors and am living in a house that has them, and am also renovating a house that will have them. If you choose something with a warmer base (taupe/beige is fine but not yellow) it will carry you through any changes to the wall colour you might want to make in the future. Go for it! Good luck.

Colour is a personal choice, but you may find it helpful to visit COLORBOND.COM, click on the Colours menu, then Monument and Dune. You will see some suggested complementary colours that might assist you. There is also the colour selector tool that may help you to visualise the options. This is found at http://colorbond.autech.com.au/onlinevisualiser/index.php?frame=residential

anaewlo - did all this just over 12 months ago so know how valuable an extra pair or eyes and a clearer head can help. The "little" things are the ones so easily missed and the ones that make you ask "what was I thinking" or "how did I miss that". You could take the tiles up higher immediately behind the hotplates, the range hood would then tie it all together and you could even have some nice artwork each side of it. The only concern I have - are the 2 tiles in the second row centred over your hotplates? Fine if they are as you will have that high part nice and even. If not, I'd a have good think about it. Otherwise, assuming you will paint the walls in a semi gloss paint, the lower tiles will take the brunt of the oil and what goes on the walls will be pretty easy to wash off, it is just a matter of wiping it down after each cooking session. There are times to match things up and there are times to blend. With your downlights, keep to white (assuming you will paint your ceilings white). this way they tend to disappear into the ceiling

My suggestion is first talk to the builder to see what instructions he gave the tiler as i'm sure he doesn't want a dissatisfied client. Most tilers will check with the builder before grouting especially when a colour is not specified in a contract. I would then ask if the grout could be replaced, from the looks of it it will only be a couple of hours work. There is nothing worse than having to look at something you are not happy with. I would not use the paint product as it will alway look like it is covering a mistake. White will look better. Make sure the mixer body is waterproofed or you will have a leak in your wall, the membrane should lap onto the body from the wall if it is done well. All the best.