ΔE 8.6, close: similar, with a visible difference side by side. Prussian Blue is a little darker, warmer than Thunderous Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Prussian Blue is a little darker, warmer than Thunderous Blue.
The same difference applies the other way round: Thunderous Blue is a little lighter, cooler.
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 Thunderous Blue on the colour wheel See Prussian Blue on the colour wheel
All matches: Thunderous Blue equivalents · Prussian Blue equivalents