ΔE 24.5, loose: different enough that you should pick on purpose. UK Light Stone is noticeably darker, much more saturated, cooler than Sand Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). UK Light Stone is noticeably darker, much more saturated, cooler than Sand Grey.
The same difference applies the other way round: Sand Grey is noticeably lighter, much more muted, warmer.
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 Sand Grey on the colour wheel See UK Light Stone on the colour wheel
All matches: Sand Grey equivalents · UK Light Stone equivalents