ΔE 9.1, close: similar, with a visible difference side by side. Plate Armour is a little darker than Plate Mail Metal.
✓ Two Thin Coats comparison chart lists these two as equivalents.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Plate Armour is a little darker than Plate Mail Metal.
The same difference applies the other way round: Plate Mail Metal 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 Plate Mail Metal on the colour wheel See Plate Armour on the colour wheel
All matches: Plate Mail Metal equivalents · Plate Armour equivalents