Flat Blue vs Pastel Blue

How close are they?

ΔE 14.7, fair: the same colour family, but not a straight swap. Pastel Blue is a little lighter, more muted, warmer than Flat Blue.

Can I use Pastel Blue instead of Flat Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Pastel Blue is a little lighter, more muted, warmer than Flat Blue.

Can I use Flat Blue instead of Pastel Blue?

The same difference applies the other way round: Flat Blue is a little darker, 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.