Mithril vs Golden Shine

How close are they?

ΔE 52.1, loose: different enough that you should pick on purpose. Golden Shine is noticeably darker, much more saturated than Mithril.

Can I use Golden Shine instead of Mithril?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 52). Golden Shine is noticeably darker, much more saturated than Mithril.

Can I use Mithril instead of Golden Shine?

The same difference applies the other way round: Mithril 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.