unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls, ExtCtrls;
type
 TForm1 = class(TForm)
  Timer1: TTimer;
  Label1: TLabel;
  procedure Timer1Timer(Sender: TObject);
 private
  { Private declarations }
 public
  { Public declarations }
 end;
var
 Form1: TForm1;
implementation
var
 r,g,b:integer;
{$R *.dfm}
procedure TForm1.Timer1Timer(Sender: TObject);
begin
 if (r<=255) and (g<=255) and (b<=255) then
 begin
  Label1.Font.Color:=RGB(r,g,b);
  //改变文字颜色
  r:=r+1;
  g:=g+1;
  b:=b+1;
 end
 else
  begin
  r:=0;
  g:=0;
  b:=0;
  end;
end;
end.