Rage Brown vs Velvet Red

How close are they?

ΔE 18.7, loose: different enough that you should pick on purpose. Velvet Red is a little darker, more muted, cooler than Rage Brown.

Can I use Velvet Red instead of Rage Brown?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Velvet Red is a little darker, more muted, cooler than Rage Brown.

Can I use Rage Brown instead of Velvet Red?

The same difference applies the other way round: Rage Brown is a little lighter, more saturated, 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.