ΔE 9.7, close: similar, with a visible difference side by side. Faded Plum is a little darker, more muted, warmer than Dechala Lilac.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Faded Plum is a little darker, more muted, warmer than Dechala Lilac.
The same difference applies the other way round: Dechala Lilac is a little lighter, more saturated, 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.
See Dechala Lilac on the colour wheel See Faded Plum on the colour wheel
All matches: Dechala Lilac equivalents · Faded Plum equivalents