ΔE 30.0, loose: different enough that you should pick on purpose. Flat Yellow is a little darker, much more saturated, cooler than Boone Tan.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Flat Yellow is a little darker, much more saturated, cooler than Boone Tan.
The same difference applies the other way round: Boone Tan is a little lighter, much more muted, 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 Boone Tan on the colour wheel See Flat Yellow on the colour wheel
All matches: Boone Tan equivalents · Flat Yellow equivalents