Paralyze Blue vs Mystic Blue

How close are they?

ΔE 22.1, loose: different enough that you should pick on purpose. Mystic Blue is noticeably darker, more muted, warmer than Paralyze Blue.

Can I use Mystic Blue instead of Paralyze Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Mystic Blue is noticeably darker, more muted, warmer than Paralyze Blue.

Can I use Paralyze Blue instead of Mystic Blue?

The same difference applies the other way round: Paralyze Blue is noticeably lighter, 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.