Balor Brown vs Yellow-Brown Ops

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Yellow-Brown Ops is a little darker, more saturated, warmer than Balor Brown.

Can I use Yellow-Brown Ops instead of Balor Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Yellow-Brown Ops is a little darker, more saturated, warmer than Balor Brown.

Can I use Balor Brown instead of Yellow-Brown Ops?

The same difference applies the other way round: Balor Brown is a little lighter, more muted, 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.