ΔE 10.7, fair: the same colour family, but not a straight swap. Oxford Blue is a little darker, more saturated, warmer than Payne’s Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Oxford Blue is a little darker, more saturated, warmer than Payne’s Grey.
The same difference applies the other way round: Payne’s Grey is a little lighter, more muted, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Payne’s Grey on the colour wheel See Oxford Blue on the colour wheel
All matches: Payne’s Grey equivalents · Oxford Blue equivalents