ΔE 6.9, close: similar, with a visible difference side by side. Bony Matter is a little darker than Matt Sepia. They are different kinds of paint: AMMO by Mig Matt Sepia is an ink, glaze or transparent paint and Army Painter Bony Matter is a one-coat contrast-style paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Bony Matter is a little darker than Matt Sepia. They are different kinds of paint.
The same difference applies the other way round: Matt Sepia 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 Matt Sepia on the colour wheel See Bony Matter on the colour wheel
All matches: Matt Sepia equivalents · Bony Matter equivalents