Gunner Camo vs Cool Blue

How close are they?

ΔE 21.4, loose: different enough that you should pick on purpose. Cool Blue is noticeably lighter, more saturated, cooler than Gunner Camo.

Can I use Cool Blue instead of Gunner Camo?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Cool Blue is noticeably lighter, more saturated, cooler than Gunner Camo.

Can I use Gunner Camo instead of Cool Blue?

The same difference applies the other way round: Gunner Camo is noticeably darker, more muted, warmer.

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.