Prompts the user to pick a color using the default color-chooser dialog box.
This scripting function has no Client Permission restrictions.
system.gui.chooseColor(initialColor [, dialogTitle])
Color initialColor - A color to use as a starting point in the color choosing popup.
String dialogTitle - The title for the color choosing popup. Defaults to "Choose Color" [optional]
Color - The new color chosen by the user.