ΔE 7.7, close: similar, with a visible difference side by side. Maggot Skin is a little darker, cooler than Rotten Yellow. They are different kinds of paint: AMMO by Mig Rotten Yellow is an opaque base/layer paint and Army Painter Maggot Skin is a one-coat contrast-style 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). Maggot Skin is a little darker, cooler than Rotten Yellow. They are different kinds of paint.
The same difference applies the other way round: Rotten Yellow is a little lighter, 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 Rotten Yellow on the colour wheel See Maggot Skin on the colour wheel
All matches: Rotten Yellow equivalents · Maggot Skin equivalents