Red vs Mahogany Ink

How close are they?

ΔE 65.4, loose: different enough that you should pick on purpose. Mahogany Ink is noticeably darker, much more muted, cooler than Red.

Can I use Mahogany Ink instead of Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 65). Mahogany Ink is noticeably darker, much more muted, cooler than Red.

Can I use Red instead of Mahogany Ink?

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