ΔE 9.1, close: similar, with a visible difference side by side. Signal Red (Metal.) is a little lighter, more saturated than Iridescent Pearl (Coarse). They are different kinds of paint: Golden Iridescent Pearl (Coarse) is a pearl paint and Vallejo Signal Red (Metal.) is a metallic, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Signal Red (Metal.) is a little lighter, more saturated than Iridescent Pearl (Coarse). They are different kinds of paint.
The same difference applies the other way round: Iridescent Pearl (Coarse) 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.
See Iridescent Pearl (Coarse) on the colour wheel See Signal Red (Metal.) on the colour wheel
All matches: Iridescent Pearl (Coarse) equivalents · Signal Red (Metal.) equivalents