The benchtop will be dark grey (the ones you see are temporary), black handles and the tiles will be white with light grey grout. The paint on the walls will stay as is (light grey). Thanks for your thoughts guys. Would anyone go all the way to the ceiling? why/why not? Does the herringbone pattern influence your decision?

Ok so depending on floor colours and overall look that she is going for I think (if she is really adamant) that the blue could work if you change the Amaro cabinets to a whiter shade - this will give it an overall crisp, oceanside feel with the warmth of the soft walnut. Otherwise I would contrast it more with a mid-tone colour splashback in grey/brown tones. Again this totally depends of her tastes... Here's a photo that you could show her with the blue splashback - granted it is a little deeper than her selection but at least she can see it on a realistic scale and of course the timber/white cabinets are flipped in this one. Hope some of that helps!

okay!!! A lot of these commenters obviously thought what I did - that the cupboards are a deep browney grey!! I think the responses would have been very different if we knew the cupboards were white. If you re-read thru the responses you will see that. Perhaps try re-posting the dilemma with a better pic. One of those original tiles may actually look ok.

I love Julie's ideas of succulents , especially the pics with several different ones in the same pot . As far as the grey , I wouldn't -- you look like you like colour and excitement , so I'd go yellow on the pots -- a similar or slightly brighter shade then the cushion on the couch or chair to the left . It would tie it all in , and make that lovely mat look more like a feature too IMO . Without knowing 'the bigger picture' ( what else is 'happening' around that wall ) , just what I see I'd be inclined to add a light either side of the door too -- stick to the same shade as the joinery ( personally , I'd go for a 'clean rustic; style with say 15 squares each side ) , or if brave ( and assuming the guttering etc is probably a similar charcoal as your door joinery ? ) , go for the same yellow as your pots -- add a Wow !