Hoard Bronze vs Radiant Platinum

How close are they?

ΔE 29.7, loose: different enough that you should pick on purpose. Radiant Platinum is noticeably lighter, much more muted, cooler than Hoard Bronze.

Can I use Radiant Platinum instead of Hoard Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Radiant Platinum is noticeably lighter, much more muted, cooler than Hoard Bronze.

Can I use Hoard Bronze instead of Radiant Platinum?

The same difference applies the other way round: Hoard Bronze 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.