Doom Metal vs Starship Steel

How close are they?

ΔE 16.8, loose: different enough that you should pick on purpose. Starship Steel is a little darker, more saturated than Doom Metal.

Can I use Starship Steel instead of Doom Metal?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Starship Steel is a little darker, more saturated than Doom Metal.

Can I use Doom Metal instead of Starship Steel?

The same difference applies the other way round: Doom Metal is a little lighter, 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.