ΔE 13.0, fair: the same colour family, but not a straight swap. Scarlet is a little darker, more saturated than Sekigahara.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Scarlet is a little darker, more saturated than Sekigahara.
The same difference applies the other way round: Sekigahara is a little lighter, 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 Sekigahara on the colour wheel See Scarlet on the colour wheel
All matches: Sekigahara equivalents · Scarlet equivalents