ΔE 12.3, fair: the same colour family, but not a straight swap. Camel Yellow is a little lighter, more saturated, cooler than Imperial Fist. They are different kinds of paint: Citadel Imperial Fist is a one-coat contrast-style paint and Tamiya Camel Yellow is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Camel Yellow is a little lighter, more saturated, cooler than Imperial Fist. They are different kinds of paint.
The same difference applies the other way round: Imperial Fist is a little darker, 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.
See Imperial Fist on the colour wheel See Camel Yellow on the colour wheel
All matches: Imperial Fist equivalents · Camel Yellow equivalents