Need a wall paint to go with Strong white!

[Namechangenecessity]

We have just had alcove cupboards and wardrobes built upstairs which we are painting in F and B strong white . We currently have Egyptian cotton (Dulux) on the walls , but I think we need something different. I’m looking for a greyish shade and the decorator suggested ammonite but I’m worried that we need more of a contrast and maybe I need something more like skimming stone? Really stuck? Any ideas pls?