ΔE 7.7, close: similar, with a visible difference side by side. Middle Stone is a little darker, more muted, cooler than RLM 79 Sand Yellow.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Middle Stone is a little darker, more muted, cooler than RLM 79 Sand Yellow.
The same difference applies the other way round: RLM 79 Sand Yellow is a little lighter, more saturated, 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 RLM 79 Sand Yellow on the colour wheel See Middle Stone on the colour wheel
All matches: RLM 79 Sand Yellow equivalents · Middle Stone equivalents