Rotten Yellow vs Screaming Skull

How close are they?

ΔE 16.8, loose: different enough that you should pick on purpose. Screaming Skull is a little darker, much more muted than Rotten Yellow.

Can I use Screaming Skull instead of Rotten Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Screaming Skull is a little darker, much more muted than Rotten Yellow.

Can I use Rotten Yellow instead of Screaming Skull?

The same difference applies the other way round: Rotten Yellow is a little lighter, much more saturated.

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.