Traitor Red vs Dark Umber

How close are they?

ΔE 9.7, close: similar, with a visible difference side by side. Dark Umber is a little darker, more saturated, warmer than Traitor Red.

Can I use Dark Umber instead of Traitor Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Dark Umber is a little darker, more saturated, warmer than Traitor Red.

Can I use Traitor Red instead of Dark Umber?

The same difference applies the other way round: Traitor Red is a little lighter, more muted, 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.