ΔE 7.5, close: similar, with a visible difference side by side. Olive Green is a little darker, more muted than Ogre Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Olive Green is a little darker, more muted than Ogre Green.
The same difference applies the other way round: Ogre Green is a little lighter, more saturated.
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 Ogre Green on the colour wheel See Olive Green on the colour wheel
All matches: Ogre Green equivalents · Olive Green equivalents