Have a read of this: https://www.idealhome.co.uk/diy-and-decorating/best-white-paint-walls-172455

One of the experts recommends a colour called Belgravia by Mylands - I’ve just bought a sample and am probably going to use it on my hall and landing. It’s a gorgeous warm off white with no other obvious colours.

Shirting - Little Greene.

All White by F&B?

Dulux milk white

Wevet by F&B.

I like Polar bear white https://www.homedepot.com/p/BEHR-6-1-2-in-x-6-1-2-in-75-Polar-Bear-Matte-Interior-Peel-and-Stick-Paint-Color-Sample-Swatch-PNSHD053/311631462?source=shoppingads&locale=en-US&mtc=Shopping-B-F_Brand-G-Multi-NA-Multi-NA-Feed-PLA-NA-NA-Catchall_PLA&cm_mmc=Shopping-B-F_Brand-G-Multi-NA-Multi-NA-Feed-PLA-NA-NA-Catchall_PLA-71700000014585962-58700001236285396-92700052972852974&gclid=CjwKCAiA8Jf-BRB-EiwAWDtEGuLLVQvCslqqsHmWg8kua5AboNSyI4MyXkoWETlIYfNJc0FoZgmFhhoCuJ4QAvD_BwE&gclsrc=aw.ds

Almost White from Wickes no undertones good coverage available in 5 litre tins and inexpensive .

I think you should go for ivory white paint.

We did our entire house in timeless haha - I would say it’s actually not blue at all in most lights (but can definitely believe it looks blue if you try it next to cream..!)

F&B All White is the purest off white I’ve found
Also F&B Wevet which has a very slight grey under stone

But of course. They look different throughout the day

+1 F&B Wevet. Pure white paint usually looks blue under certain conditions. I can't remember the technical reason for this but anyone old enough might remember housewives dipping their white washing into a solution containing a little blue bag! I suspect it's this "cold" blue effect you are trying to avoid without looking cream. I had Johnstone trade outlet colour match wevet. They add just a touch of red and yellow plus black to a white base. It looks white but never blue under any normal lighting.

Also remember to paint it on a big piece of card & move it around the room throughout the day.

Don’t paint a little swatch on the wall as it will only bring out the undertone of whatever it’s painted against

F&B All White & Wevet tick the box :-)

Thank you so much everyone . Have some more testers to try - this is the problem with too much choice these days . really appreciate you all posting

I always use "Little Greene" paint which is an eco paint and colours are quite natural and whites don't seem to have undertones. they do tester pots too. I used slaked lime for all the paintwork in my previous house. I also managed to find an interior design shop that stocked it and had large samples of paint on wood and were very helpful in advising me

Our kitchen cupboards are painted in Little Greene's Linen Wash which is a soft white. Their Shirting is like pure brilliant white, very stark.

I have used Dulux Natural Calico many times its a great off white.

Little knights paint is very natural. Have a look on their website

Tusk by Little Greene would look great with your tiles

Slaked Lime by Little Greene is a beautiful, soft, natural looking white.

Personally me was looking for good clean colors for indoors , did try many brands and CROWN was the best , I did used white CROWN CLEAN EXTREME scrubbable matt 5ltr, but there is possibility for you get tone what you like they do mixing. Paint extremely good, especially for kitchen, please look and get some samples to try https://www.crowndecoratingcentres.co.uk/paints/specialist/scrubbable/crown-trade-clean-extreme-scrubbable-matt/14832

I had a similar situation and tested various white colours. Little Green wood ash came out tops and looks fab.