Oxide Brown Light vs Tan

How close are they?

ΔE 24.7, loose: different enough that you should pick on purpose. Tan is noticeably lighter, more saturated than Oxide Brown Light.

Can I use Tan instead of Oxide Brown Light?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Tan is noticeably lighter, more saturated than Oxide Brown Light.

Can I use Oxide Brown Light instead of Tan?

The same difference applies the other way round: Oxide Brown Light is noticeably 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.