Runic Cobalt vs Mead Violet

How close are they?

ΔE 19.7, loose: different enough that you should pick on purpose. Mead Violet is a little darker, more saturated, warmer than Runic Cobalt.

Can I use Mead Violet instead of Runic Cobalt?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Mead Violet is a little darker, more saturated, warmer than Runic Cobalt.

Can I use Runic Cobalt instead of Mead Violet?

The same difference applies the other way round: Runic Cobalt is a little lighter, more muted, 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.