ΔE 14.5, fair: the same colour family, but not a straight swap. Tan is a little lighter, more muted, warmer than Sekigahara.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Tan is a little lighter, more muted, warmer than Sekigahara.
The same difference applies the other way round: Sekigahara is a little darker, more saturated, cooler.
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 Sekigahara on the colour wheel See Tan on the colour wheel
All matches: Sekigahara equivalents · Tan equivalents