Etherium Blue vs Decadent Purple

How close are they?

ΔE 17.3, loose: different enough that you should pick on purpose. Decadent Purple is a little lighter, more muted, warmer than Etherium Blue.

Can I use Decadent Purple instead of Etherium Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Decadent Purple is a little lighter, more muted, warmer than Etherium Blue.

Can I use Etherium Blue instead of Decadent Purple?

The same difference applies the other way round: Etherium Blue is a little darker, 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.