ΔE 6.3, close: similar, with a visible difference side by side. IJA Grey Green is a little lighter than Splinter Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). IJA Grey Green is a little lighter than Splinter Grey.
The same difference applies the other way round: Splinter Grey is a little darker.
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.
See Splinter Grey on the colour wheel See IJA Grey Green on the colour wheel
All matches: Splinter Grey equivalents · IJA Grey Green equivalents