ΔE 19.7, loose: different enough that you should pick on purpose. Orchid Light is noticeably lighter, more muted than Ghost Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Orchid Light is noticeably lighter, more muted than Ghost Blue.
The same difference applies the other way round: Ghost Blue is noticeably darker, 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 Ghost Blue on the colour wheel See Orchid Light on the colour wheel
All matches: Ghost Blue equivalents · Orchid Light equivalents