Greedy Gold vs Fire Opal

How close are they?

ΔE 26.9, loose: different enough that you should pick on purpose. Fire Opal is a little darker, more muted, warmer than Greedy Gold.

Can I use Fire Opal instead of Greedy Gold?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Fire Opal is a little darker, more muted, warmer than Greedy Gold.

Can I use Greedy Gold instead of Fire Opal?

The same difference applies the other way round: Greedy Gold 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.