ΔE 23.1, loose: different enough that you should pick on purpose. Screaming Skull is noticeably darker, much more muted than Pale Rider.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Screaming Skull is noticeably darker, much more muted than Pale Rider.
The same difference applies the other way round: Pale Rider is noticeably 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.
See Pale Rider on the colour wheel See Screaming Skull on the colour wheel
All matches: Pale Rider equivalents · Screaming Skull equivalents