ΔE 5.8, very close: most people won’t see a difference side by side. Primary Cyan is a little lighter than Blue Flux. They are different kinds of paint: Army Painter Blue Flux is an opaque base/layer paint and Golden Primary Cyan is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 6). Primary Cyan is a little lighter than Blue Flux. They are different kinds of paint.
The same difference applies the other way round: Blue Flux is a little darker.
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 Blue Flux on the colour wheel See Primary Cyan on the colour wheel
All matches: Blue Flux equivalents · Primary Cyan equivalents