ΔE 52.0, loose: different enough that you should pick on purpose. Mahogany Ink is noticeably darker, more saturated than Light Grey.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 52). Mahogany Ink is noticeably darker, more saturated than Light Grey.
The same difference applies the other way round: Light Grey 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 Light Grey on the colour wheel See Mahogany Ink on the colour wheel
All matches: Light Grey equivalents · Mahogany Ink equivalents