Interior Yellow Green vs Space Dust

How close are they?

ΔE 7.4, close: similar, with a visible difference side by side. Space Dust is a little lighter, more muted than Interior Yellow Green.

Can I use Space Dust instead of Interior Yellow Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Space Dust is a little lighter, more muted than Interior Yellow Green.

Can I use Interior Yellow Green instead of Space Dust?

The same difference applies the other way round: Interior Yellow Green is a little darker, more saturated.

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.