ΔE 7.7, close: similar, with a visible difference side by side. Airbrush Thinner is a little darker than White Scar.
Can I use Airbrush Thinner instead of White Scar?
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Airbrush Thinner is a little darker than White Scar.
Can I use White Scar instead of Airbrush Thinner?
The same difference applies the other way round: White Scar is a little lighter.
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.