Barren Yellow vs Skrag Brown

How close are they?

ΔE 15.6, loose: different enough that you should pick on purpose. Skrag Brown is a little darker, more saturated than Barren Yellow.

Can I use Skrag Brown instead of Barren Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Skrag Brown is a little darker, more saturated than Barren Yellow.

Can I use Barren Yellow instead of Skrag Brown?

The same difference applies the other way round: Barren Yellow is a little lighter, 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.