ΔE 9.9, close: similar, with a visible difference side by side. Caribbean Blue is more muted, cooler than Hazardous Smog.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Caribbean Blue is more muted, cooler than Hazardous Smog.
The same difference applies the other way round: Hazardous Smog 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 Hazardous Smog on the colour wheel See Caribbean Blue on the colour wheel
All matches: Hazardous Smog equivalents · Caribbean Blue equivalents