Archangel Red vs Evil Sunz Scarlet

How close are they?

ΔE 16.5, loose: different enough that you should pick on purpose. Evil Sunz Scarlet is a little darker, more muted, cooler than Archangel Red.

Can I use Evil Sunz Scarlet instead of Archangel Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Evil Sunz Scarlet is a little darker, more muted, cooler than Archangel Red.

Can I use Archangel Red instead of Evil Sunz Scarlet?

The same difference applies the other way round: Archangel Red 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.