Since 1905 all Colt revolvers were completely drop safe.
Colt's had TWO internal automatic safety features.
The first safety was the rebounding hammer system.
After firing and the trigger is allowed to move forward, the hammer is forced backward (rebounds) away from the primer and locked there.
The hammer cannot move forward again until the action is allowed to reset and the trigger pulled again.
In case the gun were dropped or the hammer struck and the rebound feature was broken or forced, Colt added a second "Positive" safety.
This is a steel bar connected to the trigger so that when the trigger is pulled it slides UP and clears the path of the hammer so it can strike the primer.
As soon as the trigger is released, the Positive safety slides DOWN in the frame and blocks the hammer so it can't move forward until the trigger is pulled again.
This safety can be seen just in front of the cocked hammer.
Until the trigger is released and the action resets the steel block prevents the hammer from moving forward.
This double automatic safety system insures that the only way the gun can fire is to deliberately pull the trigger.
This also renders the old excuse, "The gun just went off" invalid.