ΔE 9.9, close: similar, with a visible difference side by side. Light Brown is a little lighter than Harvest Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Light Brown is a little lighter than Harvest Brown.
The same difference applies the other way round: Harvest Brown 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 Harvest Brown on the colour wheel See Light Brown on the colour wheel
All matches: Harvest Brown equivalents · Light Brown equivalents