Baron Blue vs Smalt Hue

How close are they?

ΔE 8.5, close: similar, with a visible difference side by side. Smalt Hue is more saturated, warmer than Baron Blue.

Can I use Smalt Hue instead of Baron Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Smalt Hue is more saturated, warmer than Baron Blue.

Can I use Baron Blue instead of Smalt Hue?

The same difference applies the other way round: Baron Blue is more muted, 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.