ΔE 13.6, fair: the same colour family, but not a straight swap. Elysium Blue is warmer than Temple Guard Blue.
Can I use Elysium Blue instead of Temple Guard Blue?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Elysium Blue is warmer than Temple Guard Blue.
Can I use Temple Guard Blue instead of Elysium Blue?
The same difference applies the other way round: Temple Guard Blue is 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.