ΔE 6.3, close: similar, with a visible difference side by side. Transparent Red Iron Oxide is a little darker than Trollslayer Orange.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Transparent Red Iron Oxide is a little darker than Trollslayer Orange.
The same difference applies the other way round: Trollslayer Orange 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 Trollslayer Orange on the colour wheel See Transparent Red Iron Oxide on the colour wheel
All matches: Trollslayer Orange equivalents · Transparent Red Iron Oxide equivalents