ΔE 21.0, loose: different enough that you should pick on purpose. Motherlode is noticeably lighter, much more saturated than Polished Silver.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Motherlode is noticeably lighter, much more saturated than Polished Silver.
The same difference applies the other way round: Polished Silver is noticeably darker, 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.
See Polished Silver on the colour wheel See Motherlode on the colour wheel
All matches: Polished Silver equivalents · Motherlode equivalents