Hoard Bronze vs Runic Gold

How close are they?

ΔE 18.1, loose: different enough that you should pick on purpose. Runic Gold is noticeably darker, much more saturated than Hoard Bronze.

Can I use Runic Gold instead of Hoard Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Runic Gold is noticeably darker, much more saturated than Hoard Bronze.

Can I use Hoard Bronze instead of Runic Gold?

The same difference applies the other way round: Hoard Bronze is noticeably lighter, much 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.