Burnt Umber INK vs Mahogany Ink

How close are they?

ΔE 29.5, loose: different enough that you should pick on purpose. Mahogany Ink is noticeably lighter, more saturated than Burnt Umber INK.

Can I use Mahogany Ink instead of Burnt Umber INK?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Mahogany Ink is noticeably lighter, more saturated than Burnt Umber INK.

Can I use Burnt Umber INK instead of Mahogany Ink?

The same difference applies the other way round: Burnt Umber INK is noticeably darker, 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.