Balor Brown vs Quicksand Brown

How close are they?

ΔE 16.9, loose: different enough that you should pick on purpose. Quicksand Brown is a little darker, warmer than Balor Brown.

Can I use Quicksand Brown instead of Balor Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Quicksand Brown is a little darker, warmer than Balor Brown.

Can I use Balor Brown instead of Quicksand Brown?

The same difference applies the other way round: Balor Brown is a little 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.