Royal Blue vs Ultramarine

How close are they?

ΔE 14.0, fair: the same colour family, but not a straight swap. Ultramarine is more saturated, warmer than Royal Blue.

Can I use Ultramarine instead of Royal Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Ultramarine is more saturated, warmer than Royal Blue.

Can I use Royal Blue instead of Ultramarine?

The same difference applies the other way round: Royal 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.