code: function(args) {
  
                  var amount = _.isFinite(args.amount) ? args.amount : 1;
  
                  return _.template('<filter><feColorMatrix type="saturate" values="${amount}"/></filter>', {
                      amount: 1 - amount
                  });
              }
docs: `amount` ... the proportion of the conversion. A value of 0 is completely un-saturated. A value of 1 leaves the input unchanged.