ΔE 8.0, close: similar, with a visible difference side by side. Green Gold is more saturated than Nurgle's Rot. They are different kinds of paint: Citadel Nurgle's Rot is a technical paint or medium and Golden Green Gold is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Green Gold is more saturated than Nurgle's Rot. They are different kinds of paint.
The same difference applies the other way round: Nurgle's Rot is 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 Nurgle's Rot on the colour wheel See Green Gold on the colour wheel
All matches: Nurgle's Rot equivalents · Green Gold equivalents