Satchel Brown vs Deep Purple

How close are they?

ΔE 23.5, loose: different enough that you should pick on purpose. Deep Purple is more saturated, cooler than Satchel Brown.

Can I use Deep Purple instead of Satchel Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Deep Purple is more saturated, cooler than Satchel Brown.

Can I use Satchel Brown instead of Deep Purple?

The same difference applies the other way round: Satchel Brown is more muted, warmer.

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.