Longbeard Grey vs Titan Green Pale

How close are they?

ΔE 16.0, loose: different enough that you should pick on purpose. Titan Green Pale is noticeably lighter, more saturated than Longbeard Grey.

Can I use Titan Green Pale instead of Longbeard Grey?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Titan Green Pale is noticeably lighter, more saturated than Longbeard Grey.

Can I use Longbeard Grey instead of Titan Green Pale?

The same difference applies the other way round: Longbeard Grey is noticeably 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.