ΔE 28.5, loose: different enough that you should pick on purpose. Ruby Red is noticeably darker, much more muted, cooler than Sacred Scarlet.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Ruby Red is noticeably darker, much more muted, cooler than Sacred Scarlet.
The same difference applies the other way round: Sacred Scarlet is noticeably lighter, much 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.
See Sacred Scarlet on the colour wheel See Ruby Red on the colour wheel
All matches: Sacred Scarlet equivalents · Ruby Red equivalents