ΔE 8.8, close: similar, with a visible difference side by side. Dark Battle Dress is a little lighter, more saturated than Starship Sludge Bay.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Dark Battle Dress is a little lighter, more saturated than Starship Sludge Bay.
The same difference applies the other way round: Starship Sludge Bay is a little darker, 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 Starship Sludge Bay on the colour wheel See Dark Battle Dress on the colour wheel
All matches: Starship Sludge Bay equivalents · Dark Battle Dress equivalents