ΔE 5.8, very close: most people won’t see a difference side by side. Seraphim Sepia is a little darker than Desert Yellow. They are different kinds of paint: AMMO by Mig Desert Yellow is an opaque base/layer paint and Citadel Seraphim Sepia is a wash/shade, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 6). Seraphim Sepia is a little darker than Desert Yellow. They are different kinds of paint.
The same difference applies the other way round: Desert Yellow is a little lighter.
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 Desert Yellow on the colour wheel See Seraphim Sepia on the colour wheel
All matches: Desert Yellow equivalents · Seraphim Sepia equivalents