Democracies don't have violent revolutions, period.
h really? I can list off a slew of them, starting with both England and the US Colonies. Because I would call not only the English Civil War a violent revolution, they do not call what the US colonies did the "Revolutionary War" peaceful either.
One really has to be careful making statements like that. Especially when those who know history can prove them to be false. You also have the Yellow Revolution, and if I want to think on it can come up with many more. But you should know that simply believing in axioms does not make them real.
Especially since "Democracies" are in general the most unstable for of government there are. Which is why so many of them fail.