Light Blue vs Psychic Shock

How close are they?

ΔE 15.1, loose: different enough that you should pick on purpose. Psychic Shock is noticeably darker, more muted, warmer than Light Blue.

Can I use Psychic Shock instead of Light Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Psychic Shock is noticeably darker, more muted, warmer than Light Blue.

Can I use Light Blue instead of Psychic Shock?

The same difference applies the other way round: Light 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.