type
 TSomeControl = class(TCustomControl)
 private

 protected

 public

   constructor Create(AOwner: TComponent); override;

 published

 end;

procedure Register;

implementation

procedure Register;
begin
 RegisterComponents('My Components', [TSomeControl]);
end;

constructor TSomeControl.Create(AOwner: TComponent);
begin
 inherited;

 Color:= clRed;
end;