ΔE 7.4, close: similar, with a visible difference side by side. Brown Sand is a little darker than Denison Tan Base.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Brown Sand is a little darker than Denison Tan Base.
The same difference applies the other way round: Denison Tan Base is a little lighter.
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 Denison Tan Base on the colour wheel See Brown Sand on the colour wheel
All matches: Denison Tan Base equivalents · Brown Sand equivalents