Inktense Brown vs Ink Green

How close are they?

ΔE 50.3, loose: different enough that you should pick on purpose. Ink Green is noticeably lighter, much more saturated than Inktense Brown.

Can I use Ink Green instead of Inktense Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 50). Ink Green is noticeably lighter, much more saturated than Inktense Brown.

Can I use Inktense Brown instead of Ink Green?

The same difference applies the other way round: Inktense Brown is noticeably darker, much 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.