Rakarth Flesh vs Trollblood Highlight

How close are they?

ΔE 7.6, close: similar, with a visible difference side by side. Trollblood Highlight is a little lighter, cooler than Rakarth Flesh.

Can I use Trollblood Highlight instead of Rakarth Flesh?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Trollblood Highlight is a little lighter, cooler than Rakarth Flesh.

Can I use Rakarth Flesh instead of Trollblood Highlight?

The same difference applies the other way round: Rakarth Flesh is a little darker, warmer.

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.