ΔE 9.8, close: similar, with a visible difference side by side. Arctic Gem is a little darker, warmer than Saphire Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Arctic Gem is a little darker, warmer than Saphire Blue.
The same difference applies the other way round: Saphire Blue is a little lighter, 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 Saphire Blue on the colour wheel See Arctic Gem on the colour wheel
All matches: Saphire Blue equivalents · Arctic Gem equivalents