Eidolon Purple Clear vs Anthraquinone Blue

How close are they?

ΔE 26.5, loose: different enough that you should pick on purpose. Anthraquinone Blue is noticeably darker, cooler than Eidolon Purple Clear.

Can I use Anthraquinone Blue instead of Eidolon Purple Clear?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Anthraquinone Blue is noticeably darker, cooler than Eidolon Purple Clear.

Can I use Eidolon Purple Clear instead of Anthraquinone Blue?

The same difference applies the other way round: Eidolon Purple Clear is noticeably lighter, 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.