ΔE 10.6, fair: the same colour family, but not a straight swap. Flat Blue is a little lighter, more muted than Omega Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Flat Blue is a little lighter, more muted than Omega Blue.
The same difference applies the other way round: Omega Blue is a little 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 Omega Blue on the colour wheel See Flat Blue on the colour wheel
All matches: Omega Blue equivalents · Flat Blue equivalents