ΔE 32.6, loose: different enough that you should pick on purpose. Warm Brown is much more muted, warmer than Sigvald Burgundy.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Warm Brown is much more muted, warmer than Sigvald Burgundy.
The same difference applies the other way round: Sigvald Burgundy is much 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 Sigvald Burgundy on the colour wheel See Warm Brown on the colour wheel
All matches: Sigvald Burgundy equivalents · Warm Brown equivalents