ΔE 15.1, loose: different enough that you should pick on purpose. Leather White is noticeably darker, more saturated than Matt White.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Leather White is noticeably darker, more saturated than Matt White.
The same difference applies the other way round: Matt White is noticeably lighter, more muted.
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 Matt White on the colour wheel See Leather White on the colour wheel
All matches: Matt White equivalents · Leather White equivalents