Naphthol Pink vs Mahogany Ink

How close are they?

ΔE 63.0, loose: different enough that you should pick on purpose. Mahogany Ink is noticeably darker, much more muted than Naphthol Pink.

Can I use Mahogany Ink instead of Naphthol Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 63). Mahogany Ink is noticeably darker, much more muted than Naphthol Pink.

Can I use Naphthol Pink instead of Mahogany Ink?

The same difference applies the other way round: Naphthol Pink is noticeably lighter, much more saturated.

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.