ΔE 7.4, close: similar, with a visible difference side by side. Flow Improver is a little darker, more muted than Insignia White FS 17875.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Flow Improver is a little darker, more muted than Insignia White FS 17875.
The same difference applies the other way round: Insignia White FS 17875 is a little lighter, 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 Insignia White FS 17875 on the colour wheel See Flow Improver on the colour wheel
All matches: Insignia White FS 17875 equivalents · Flow Improver equivalents