Tallarn Sand vs Iroko

How close are they?

ΔE 9.8, close: similar, with a visible difference side by side. Iroko is a little lighter, more saturated than Tallarn Sand.

Can I use Iroko instead of Tallarn Sand?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Iroko is a little lighter, more saturated than Tallarn Sand.

Can I use Tallarn Sand instead of Iroko?

The same difference applies the other way round: Tallarn Sand is a little darker, 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.