ΔE 14.7, fair: the same colour family, but not a straight swap. Burnt Sienna is a little lighter, much more saturated, warmer than Knight-Questor Flesh. They are different kinds of paint: Citadel Knight-Questor Flesh is an opaque base/layer paint and Golden Burnt Sienna is an ink, glaze or transparent 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 15). Burnt Sienna is a little lighter, much more saturated, warmer than Knight-Questor Flesh. They are different kinds of paint.
The same difference applies the other way round: Knight-Questor Flesh is a little darker, much more muted, 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.
See Knight-Questor Flesh on the colour wheel See Burnt Sienna on the colour wheel
All matches: Knight-Questor Flesh equivalents · Burnt Sienna equivalents