ΔE 8.5, close: similar, with a visible difference side by side. Flat Yellow is a little lighter, more saturated than Golden Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Flat Yellow is a little lighter, more saturated than Golden Brown.
The same difference applies the other way round: Golden Brown is a little darker, more muted.
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 Golden Brown on the colour wheel See Flat Yellow on the colour wheel
All matches: Golden Brown equivalents · Flat Yellow equivalents