Brigandine Brown vs Burnt Sienna Umber

How close are they?

ΔE 6.3, close: similar, with a visible difference side by side. Burnt Sienna Umber is a little lighter, more saturated than Brigandine Brown.

Can I use Burnt Sienna Umber instead of Brigandine Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Burnt Sienna Umber is a little lighter, more saturated than Brigandine Brown.

Can I use Brigandine Brown instead of Burnt Sienna Umber?

The same difference applies the other way round: Brigandine Brown is a little darker, 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.