Eye of Terror vs Old Rose

How close are they?

ΔE 18.1, loose: different enough that you should pick on purpose. Old Rose is a little darker, more muted, warmer than Eye of Terror.

Can I use Old Rose instead of Eye of Terror?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Old Rose is a little darker, more muted, warmer than Eye of Terror.

Can I use Eye of Terror instead of Old Rose?

The same difference applies the other way round: Eye of Terror 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.