What had to die to make Cleopatra's favorite color?

It is assumed that purple was Cleopatra's favorite color and in order to get this color, thousands of tiny mollusks or shell fish had to die as the pigment to make the purple dye came from their shells. However, as for purple being Cleo's favorite color, who knows? Purple was a royal color, used by kings and queens and rulers. Cleopatra certainly used the color to flout her authority, even on the sails of her ships, but if it were her personal favorite is unknown.