Skrag Brown vs Mars Yellow

How close are they?

ΔE 7.8, close: similar, with a visible difference side by side. Mars Yellow is more muted than Skrag Brown.

Can I use Mars Yellow instead of Skrag Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Mars Yellow is more muted than Skrag Brown.

Can I use Skrag Brown instead of Mars Yellow?

The same difference applies the other way round: Skrag Brown is more saturated.

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.