Joridyn Turquoise vs Light Sea Blue

How close are they?

ΔE 16.3, loose: different enough that you should pick on purpose. Light Sea Blue is noticeably lighter, more saturated than Joridyn Turquoise.

Can I use Light Sea Blue instead of Joridyn Turquoise?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Light Sea Blue is noticeably lighter, more saturated than Joridyn Turquoise.

Can I use Joridyn Turquoise instead of Light Sea Blue?

The same difference applies the other way round: Joridyn Turquoise is noticeably darker, more muted.

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.