Triumphant Navy vs Eldandil Violet

How close are they?

ΔE 14.7, fair: the same colour family, but not a straight swap. Eldandil Violet is a little lighter, warmer than Triumphant Navy.

Can I use Eldandil Violet instead of Triumphant Navy?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Eldandil Violet is a little lighter, warmer than Triumphant Navy.

Can I use Triumphant Navy instead of Eldandil Violet?

The same difference applies the other way round: Triumphant Navy is a little darker, 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.