ΔE 29.2, loose: different enough that you should pick on purpose. Caesar Red is a little lighter, cooler than True Copper.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Caesar Red is a little lighter, cooler than True Copper.
The same difference applies the other way round: True Copper is a little darker, 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.
See True Copper on the colour wheel See Caesar Red on the colour wheel
All matches: True Copper equivalents · Caesar Red equivalents