ΔE 21.1, loose: different enough that you should pick on purpose. Pastel Green is noticeably lighter, more muted, warmer than Chromium Oxide Green Dark.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Pastel Green is noticeably lighter, more muted, warmer than Chromium Oxide Green Dark.
The same difference applies the other way round: Chromium Oxide Green Dark is noticeably darker, more saturated, 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.
See Chromium Oxide Green Dark on the colour wheel See Pastel Green on the colour wheel
All matches: Chromium Oxide Green Dark equivalents · Pastel Green equivalents