ΔE 15.6, loose: different enough that you should pick on purpose. Walnut Brown is a little darker, much more muted, warmer than Gal Vorbak Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Walnut Brown is a little darker, much more muted, warmer than Gal Vorbak Red.
The same difference applies the other way round: Gal Vorbak Red is a little lighter, much more saturated, 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.
See Gal Vorbak Red on the colour wheel See Walnut Brown on the colour wheel
All matches: Gal Vorbak Red equivalents · Walnut Brown equivalents