Screaming Skull vs Light Orange

How close are they?

ΔE 15.7, loose: different enough that you should pick on purpose. Light Orange is a little lighter, more saturated, warmer than Screaming Skull.

Can I use Light Orange instead of Screaming Skull?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Light Orange is a little lighter, more saturated, warmer than Screaming Skull.

Can I use Screaming Skull instead of Light Orange?

The same difference applies the other way round: Screaming Skull is a little darker, more muted, cooler.

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.