Orgoth Bronze vs Old Gold

How close are they?

ΔE 15.5, loose: different enough that you should pick on purpose. Old Gold is noticeably darker, warmer than Orgoth Bronze.

Can I use Old Gold instead of Orgoth Bronze?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Old Gold is noticeably darker, warmer than Orgoth Bronze.

Can I use Orgoth Bronze instead of Old Gold?

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