Dark Highlights vs Charred Brown

How close are they?

ΔE 6.2, close: similar, with a visible difference side by side. Charred Brown is more saturated than Dark Highlights.

Can I use Charred Brown instead of Dark Highlights?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Charred Brown is more saturated than Dark Highlights.

Can I use Dark Highlights instead of Charred Brown?

The same difference applies the other way round: Dark Highlights is 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.