ΔE 12.2, fair: the same colour family, but not a straight swap. Transparent Ochre is a little darker, more saturated than Tallarn Sand. They are different kinds of paint: Citadel Tallarn Sand is an opaque base/layer paint and Green Stuff World Transparent Ochre is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Transparent Ochre is a little darker, more saturated than Tallarn Sand. They are different kinds of paint.
The same difference applies the other way round: Tallarn Sand is a little lighter, 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.
See Tallarn Sand on the colour wheel See Transparent Ochre on the colour wheel
All matches: Tallarn Sand equivalents · Transparent Ochre equivalents