Radiant Platinum vs Aged Metal

How close are they?

ΔE 16.0, loose: different enough that you should pick on purpose. Aged Metal is much more saturated, warmer than Radiant Platinum.

Can I use Aged Metal instead of Radiant Platinum?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Aged Metal is much more saturated, warmer than Radiant Platinum.

Can I use Radiant Platinum instead of Aged Metal?

The same difference applies the other way round: Radiant Platinum is much more muted, 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.