Thunderous Blue vs Grey Blue

How close are they?

ΔE 10.9, fair: the same colour family, but not a straight swap. Grey Blue is a little lighter, more muted than Thunderous Blue.

✓ Two Thin Coats comparison chart lists these two as equivalents.

Can I use Grey Blue instead of Thunderous Blue?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Grey Blue is a little lighter, more muted than Thunderous Blue.

Can I use Thunderous Blue instead of Grey Blue?

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

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.