ΔE 8.5, close: similar, with a visible difference side by side. Signal Blue is more muted, cooler than Bluegrey Dusk.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Signal Blue is more muted, cooler than Bluegrey Dusk.
The same difference applies the other way round: Bluegrey Dusk is more saturated, warmer.
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 Bluegrey Dusk on the colour wheel See Signal Blue on the colour wheel
All matches: Bluegrey Dusk equivalents · Signal Blue equivalents