Temple Guard Blue vs Ironhull Grey

How close are they?

ΔE 25.3, loose: different enough that you should pick on purpose. Ironhull Grey is noticeably lighter, much more muted than Temple Guard Blue.

Can I use Ironhull Grey instead of Temple Guard Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Ironhull Grey is noticeably lighter, much more muted than Temple Guard Blue.

Can I use Temple Guard Blue instead of Ironhull Grey?

The same difference applies the other way round: Temple Guard Blue is noticeably darker, much 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.