Dont think Grey is ever going to blend with mustard. I'd wait until you can do a proper job. Dulux Miller Mood and Milton Moon are very popular.

Thank you Lesley...l always thought, Surfmist was more towrads white.looks like surfmist has some hint of grey..I might have to look for some other color which is more white than grey

If you were selling , are you sure you will recoup the extra $$$$ ? Get it wrong , and a potential buyer will walk and/or offer $50k less , whereas if you leave it as it is , they will know it needs replacing , offer $10k less , but you have gotten an offer ! Just me , but what I would do is rip up the fake tile lino in the foyer ( I assume it is lino -- it doesn't look to be 'proper' tiled ? ) , and do that in a darkish timber laminate -- slightly lighter than the front door , slightly darker than the stairs . Or go really dark -- almost a dark weathered grey or a similar dark brown to the drawer unit in the lounge -- the rest of the colourings will lighten it a bit , but it will all tie in . OR actually tile it , maybe a black or charcoal gloss marble or marble effect with lighter streaks through it ? The house and colourings look an older style , this continues that theme , but I feel white or beige tiles would look too bland . $2k max instead of $10k -- marble tiles may be more than $2k , but up to you .

I would look at a the following cabinet colours. These are Sherwin Williams colours, which is now under the Wattyl brand. Your paint specialist should be able to mix colour. With your busy quartz and the Saltillo floor something soft in the white to pastel green would suit.