Sulfuric Yellow vs Bile Green

How close are they?

ΔE 22.8, loose: different enough that you should pick on purpose. Bile Green is noticeably lighter, much more saturated, cooler than Sulfuric Yellow.

Can I use Bile Green instead of Sulfuric Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Bile Green is noticeably lighter, much more saturated, cooler than Sulfuric Yellow.

Can I use Sulfuric Yellow instead of Bile Green?

The same difference applies the other way round: Sulfuric Yellow is noticeably darker, much more muted, 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.