Kantor Blue vs Turquoise Deep

How close are they?

ΔE 22.7, loose: different enough that you should pick on purpose. Turquoise Deep is a little lighter, much more muted, cooler than Kantor Blue.

Can I use Turquoise Deep instead of Kantor Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Turquoise Deep is a little lighter, much more muted, cooler than Kantor Blue.

Can I use Kantor Blue instead of Turquoise Deep?

The same difference applies the other way round: Kantor Blue is a little darker, much more saturated, warmer.

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.