Majestic Fortress vs Traitor Green

How close are they?

ΔE 28.0, loose: different enough that you should pick on purpose. Traitor Green is noticeably lighter, more muted, warmer than Majestic Fortress.

Can I use Traitor Green instead of Majestic Fortress?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Traitor Green is noticeably lighter, more muted, warmer than Majestic Fortress.

Can I use Majestic Fortress instead of Traitor Green?

The same difference applies the other way round: Majestic Fortress is noticeably darker, more saturated, cooler.

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.