ΔE 12.8, fair: the same colour family, but not a straight swap. Titanium Silver is a little lighter, more saturated than Mithril.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Titanium Silver is a little lighter, more saturated than Mithril.
The same difference applies the other way round: Mithril is a little darker, more muted.
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 Mithril on the colour wheel See Titanium Silver on the colour wheel
All matches: Mithril equivalents · Titanium Silver equivalents