Viper Brown vs Tan

How close are they?

ΔE 7.8, close: similar, with a visible difference side by side. Tan is a little lighter, more saturated than Viper Brown.

Can I use Tan instead of Viper Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Tan is a little lighter, more saturated than Viper Brown.

Can I use Viper Brown instead of Tan?

The same difference applies the other way round: Viper Brown is a little darker, 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.