Pixie Pink vs Cobalt Violet Hue

How close are they?

ΔE 28.9, loose: different enough that you should pick on purpose. Cobalt Violet Hue is noticeably darker, more muted, warmer than Pixie Pink.

Can I use Cobalt Violet Hue instead of Pixie Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Cobalt Violet Hue is noticeably darker, more muted, warmer than Pixie Pink.

Can I use Pixie Pink instead of Cobalt Violet Hue?

The same difference applies the other way round: Pixie Pink 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.