Sigvald Burgundy vs Dark Brown

How close are they?

ΔE 32.5, loose: different enough that you should pick on purpose. Dark Brown is a little darker, much more muted, warmer than Sigvald Burgundy.

Can I use Dark Brown instead of Sigvald Burgundy?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Dark Brown is a little darker, much more muted, warmer than Sigvald Burgundy.

Can I use Sigvald Burgundy instead of Dark Brown?

The same difference applies the other way round: Sigvald Burgundy is a little lighter, 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.