Surf Aqua vs Medium Grey Blue

How close are they?

ΔE 14.5, fair: the same colour family, but not a straight swap. Medium Grey Blue is more muted, warmer than Surf Aqua.

Can I use Medium Grey Blue instead of Surf Aqua?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Medium Grey Blue is more muted, warmer than Surf Aqua.

Can I use Surf Aqua instead of Medium Grey Blue?

The same difference applies the other way round: Surf Aqua is more saturated, 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.