Inktense Chestnut vs Ink Red

How close are they?

ΔE 19.0, loose: different enough that you should pick on purpose. Ink Red is a little darker, much more saturated, cooler than Inktense Chestnut.

Can I use Ink Red instead of Inktense Chestnut?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Ink Red is a little darker, much more saturated, cooler than Inktense Chestnut.

Can I use Inktense Chestnut instead of Ink Red?

The same difference applies the other way round: Inktense Chestnut is a little lighter, much more muted, 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.