ΔE 51.6, loose: different enough that you should pick on purpose. Casandora Yellow is noticeably lighter, much more saturated, cooler than Soft Tone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 52). Casandora Yellow is noticeably lighter, much more saturated, cooler than Soft Tone.
The same difference applies the other way round: Soft Tone is noticeably darker, much more muted, 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 Soft Tone on the colour wheel See Casandora Yellow on the colour wheel
All matches: Soft Tone equivalents · Casandora Yellow equivalents