Death Metal vs Grave Robber

How close are they?

ΔE 16.5, loose: different enough that you should pick on purpose. Grave Robber is a little lighter, much more saturated than Death Metal.

Can I use Grave Robber instead of Death Metal?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Grave Robber is a little lighter, much more saturated than Death Metal.

Can I use Death Metal instead of Grave Robber?

The same difference applies the other way round: Death Metal is a little darker, much 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.