ΔE 10.5, fair: the same colour family, but not a straight swap. Dungeon Stone Grey is noticeably darker than Uniform Grey.
Can I use Dungeon Stone Grey instead of Uniform Grey?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Dungeon Stone Grey is noticeably darker than Uniform Grey.
Can I use Uniform Grey instead of Dungeon Stone Grey?
The same difference applies the other way round: Uniform Grey is noticeably 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.