ΔE 10.4, fair: the same colour family, but not a straight swap. Maggot Skin is a little darker than Slime Yellow. They are different kinds of paint: AMMO by Mig Slime 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.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Maggot Skin is a little darker than Slime Yellow. They are different kinds of paint.
The same difference applies the other way round: Slime Yellow is a little lighter.
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 Slime Yellow on the colour wheel See Maggot Skin on the colour wheel
All matches: Slime Yellow equivalents · Maggot Skin equivalents