Imperial Fist vs Bronze Yellow

How close are they?

ΔE 23.6, loose: different enough that you should pick on purpose. Bronze Yellow is a little darker, much more muted, cooler than Imperial Fist.

Can I use Bronze Yellow instead of Imperial Fist?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Bronze Yellow is a little darker, much more muted, cooler than Imperial Fist.

Can I use Imperial Fist instead of Bronze Yellow?

The same difference applies the other way round: Imperial Fist is a little lighter, much more saturated, 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.