The only Colt's that aren't safe to dry fire are the Trooper Mark III, Mark V, and King Cobra.
I assume that would include the Anaconda.
Problem withe them is the firing pin "might" break, and if it does, it requires a factory replacement due to the need for a special press to pres the old pin out and install a new one without damaging the frame.
Some of us have Colt Pythons and older models like the Official Police that have been dry fired hundreds of times without damage.
To be safe, "just in case" use snap caps.