Spartan Bronze vs Aged Metal

How close are they?

ΔE 18.8, loose: different enough that you should pick on purpose. Aged Metal is a little lighter, cooler than Spartan Bronze.

Can I use Aged Metal instead of Spartan Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Aged Metal is a little lighter, cooler than Spartan Bronze.

Can I use Spartan Bronze instead of Aged Metal?

The same difference applies the other way round: Spartan Bronze is a little darker, 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.