ΔE 13.8, fair: the same colour family, but not a straight swap. Ray Gun Glow is a little lighter, more muted, warmer than Shieldwall Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Ray Gun Glow is a little lighter, more muted, warmer than Shieldwall Blue.
The same difference applies the other way round: Shieldwall Blue is a little 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 Shieldwall Blue on the colour wheel See Ray Gun Glow on the colour wheel
All matches: Shieldwall Blue equivalents · Ray Gun Glow equivalents