Flickering Flame vs Ochre Desert

How close are they?

ΔE 9.0, close: similar, with a visible difference side by side. Ochre Desert is a little darker than Flickering Flame.

Can I use Ochre Desert instead of Flickering Flame?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ochre Desert is a little darker than Flickering Flame.

Can I use Flickering Flame instead of Ochre Desert?

The same difference applies the other way round: Flickering Flame is a little lighter.

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.