Cygnus Yellow vs Bile Green

How close are they?

ΔE 11.1, fair: the same colour family, but not a straight swap. Bile Green is a little lighter, more saturated than Cygnus Yellow.

Can I use Bile Green instead of Cygnus Yellow?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Bile Green is a little lighter, more saturated than Cygnus Yellow.

Can I use Cygnus Yellow instead of Bile Green?

The same difference applies the other way round: Cygnus Yellow is a little darker, more muted.

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.