Glittering Green vs Omega Blue

How close are they?

ΔE 46.1, loose: different enough that you should pick on purpose. Omega Blue is noticeably lighter, much more muted, cooler than Glittering Green.

Can I use Omega Blue instead of Glittering Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 46). Omega Blue is noticeably lighter, much more muted, cooler than Glittering Green.

Can I use Glittering Green instead of Omega Blue?

The same difference applies the other way round: Glittering Green is noticeably darker, much more saturated, warmer.

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.