ΔE 14.3, fair: the same colour family, but not a straight swap. Primary Yellow is noticeably lighter, more saturated than Charming Chartreuse. They are different kinds of paint: Army Painter Charming Chartreuse is a one-coat contrast-style paint and Golden Primary Yellow 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 14). Primary Yellow is noticeably lighter, more saturated than Charming Chartreuse. They are different kinds of paint.
The same difference applies the other way round: Charming Chartreuse is noticeably darker, more muted.
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 Charming Chartreuse on the colour wheel See Primary Yellow on the colour wheel
All matches: Charming Chartreuse equivalents · Primary Yellow equivalents