Count of Tuscany vs Emperor's Children

How close are they?

ΔE 31.4, loose: different enough that you should pick on purpose. Emperor's Children is a little darker, cooler than Count of Tuscany.

Can I use Emperor's Children instead of Count of Tuscany?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 31). Emperor's Children is a little darker, cooler than Count of Tuscany.

Can I use Count of Tuscany instead of Emperor's Children?

The same difference applies the other way round: Count of Tuscany is a little lighter, 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.