ΔE 24.6, loose: different enough that you should pick on purpose. Gladius Bronze is noticeably lighter, more muted, warmer than Retributor Armour.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Gladius Bronze is noticeably lighter, more muted, warmer than Retributor Armour.
The same difference applies the other way round: Retributor Armour 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.
See Retributor Armour on the colour wheel See Gladius Bronze on the colour wheel
All matches: Retributor Armour equivalents · Gladius Bronze equivalents