ΔE 6.4, close: similar, with a visible difference side by side. Light Blue RLM78 is a little lighter, cooler than Dark Green-Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Light Blue RLM78 is a little lighter, cooler than Dark Green-Grey.
The same difference applies the other way round: Dark Green-Grey is a little darker, 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.
See Dark Green-Grey on the colour wheel See Light Blue RLM78 on the colour wheel
All matches: Dark Green-Grey equivalents · Light Blue RLM78 equivalents