code: function(args) {
  
                  var amount = Number.isFinite(args.amount) ? args.amount : 1;
  
                  return joint.util.template('<filter><feComponentTransfer><feFuncR type="linear" slope="${amount}" intercept="${amount2}"/><feFuncG type="linear" slope="${amount}" intercept="${amount2}"/><feFuncB type="linear" slope="${amount}" intercept="${amount2}"/></feComponentTransfer></filter>')({
                      amount: amount,
                      amount2: .5 - amount / 2
                  });
              }
docs: `amount` ... proportion of the conversion (1). A value of 0 will create an image that is completely black. A value of 1 (default) leaves the input unchanged.