Armageddon Dust vs Unbleached Titanium

How close are they?

ΔE 33.6, loose: different enough that you should pick on purpose. Unbleached Titanium is noticeably lighter, more muted than Armageddon Dust.

Can I use Unbleached Titanium instead of Armageddon Dust?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 34). Unbleached Titanium is noticeably lighter, more muted than Armageddon Dust.

Can I use Armageddon Dust instead of Unbleached Titanium?

The same difference applies the other way round: Armageddon Dust is noticeably 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.