ΔE 9.7, close: similar, with a visible difference side by side. Blue FS15050 is a little lighter, more saturated, cooler than Terrestrial Titan.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Blue FS15050 is a little lighter, more saturated, cooler than Terrestrial Titan.
The same difference applies the other way round: Terrestrial Titan is a little darker, more muted, warmer.
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 Terrestrial Titan on the colour wheel See Blue FS15050 on the colour wheel
All matches: Terrestrial Titan equivalents · Blue FS15050 equivalents