ΔE 8.0, close: similar, with a visible difference side by side. Obsidian Black is a little darker than Iridescent Silver (Fine). They are different kinds of paint: Golden Iridescent Silver (Fine) is a pearl paint and Vallejo Obsidian Black 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 8). Obsidian Black is a little darker than Iridescent Silver (Fine). They are different kinds of paint.
The same difference applies the other way round: Iridescent Silver (Fine) 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 Iridescent Silver (Fine) on the colour wheel See Obsidian Black on the colour wheel
All matches: Iridescent Silver (Fine) equivalents · Obsidian Black equivalents