[compuin]

Hola,

Lo consegui haciendo de esta manera

Código Delphi [-]
unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
     canvas.pen.color:= clred;
     canvas.pen.width:= 10;
     canvas.brush.color := clfuchsia;
     canvas.ellipse(clientwidth div 2, 0,clientwidth, clientheight);
end;

end.