ΔE 23.0, loose: different enough that you should pick on purpose. Ultramarine Violet is a little darker, much more saturated, cooler than Dechala Lilac.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Ultramarine Violet is a little darker, much more saturated, cooler than Dechala Lilac.
The same difference applies the other way round: Dechala Lilac is a little lighter, much 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 Dechala Lilac on the colour wheel See Ultramarine Violet on the colour wheel
All matches: Dechala Lilac equivalents · Ultramarine Violet equivalents