Aggaros Dunes vs Phoenix Feather

How close are they?

ΔE 20.7, loose: different enough that you should pick on purpose. Phoenix Feather is a little darker, more muted, warmer than Aggaros Dunes.

Can I use Phoenix Feather instead of Aggaros Dunes?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Phoenix Feather is a little darker, more muted, warmer than Aggaros Dunes.

Can I use Aggaros Dunes instead of Phoenix Feather?

The same difference applies the other way round: Aggaros Dunes is a little 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.