ΔE 17.1, loose: different enough that you should pick on purpose. Bright Brass (Met.) is a little lighter, more muted than Motherlode.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Bright Brass (Met.) is a little lighter, more muted than Motherlode.
The same difference applies the other way round: Motherlode is a little darker, more saturated.
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 Motherlode on the colour wheel See Bright Brass (Met.) on the colour wheel
All matches: Motherlode equivalents · Bright Brass (Met.) equivalents