Thornwood Green vs Splinter Green

How close are they?

ΔE 15.1, loose: different enough that you should pick on purpose. Splinter Green is more saturated, cooler than Thornwood Green.

Can I use Splinter Green instead of Thornwood Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Splinter Green is more saturated, cooler than Thornwood Green.

Can I use Thornwood Green instead of Splinter Green?

The same difference applies the other way round: Thornwood Green is 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.