Burnt Umber INK vs Ink Black Green

How close are they?

ΔE 19.7, loose: different enough that you should pick on purpose. Ink Black Green is noticeably lighter, more saturated than Burnt Umber INK.

Can I use Ink Black Green instead of Burnt Umber INK?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Ink Black Green is noticeably lighter, more saturated than Burnt Umber INK.

Can I use Burnt Umber INK instead of Ink Black Green?

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.