ΔE 18.8, loose: different enough that you should pick on purpose. Faded Ultramarine is a little lighter, more muted, warmer than Electric Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Faded Ultramarine is a little lighter, more muted, warmer than Electric Blue.
The same difference applies the other way round: Electric Blue is a little darker, 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 Electric Blue on the colour wheel See Faded Ultramarine on the colour wheel
All matches: Electric Blue equivalents · Faded Ultramarine equivalents