Glittering Green vs Twin Sons

How close are they?

ΔE 22.4, loose: different enough that you should pick on purpose. Twin Sons is noticeably lighter, more saturated than Glittering Green.

Can I use Twin Sons instead of Glittering Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Twin Sons is noticeably lighter, more saturated than Glittering Green.

Can I use Glittering Green instead of Twin Sons?

The same difference applies the other way round: Glittering Green 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.