ΔE 10.4, fair: the same colour family, but not a straight swap. Space Dust is warmer than Matt Light Yellow. They are different kinds of paint: AMMO by Mig Matt Light Yellow is an ink, glaze or transparent paint and Army Painter Space Dust is an opaque base/layer 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). Space Dust is warmer than Matt Light Yellow. They are different kinds of paint.
The same difference applies the other way round: Matt Light Yellow is cooler.
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 Matt Light Yellow on the colour wheel See Space Dust on the colour wheel
All matches: Matt Light Yellow equivalents · Space Dust equivalents