Код создания палитры

var

  Form1: TForm1;
  blueVal: Byte;
  BluePalette: HPalette;
implementation


{$R *.DFM}

procedure
 TForm1.FormCreate(Sender: TObject);
var


  LogicalPalette: PLogPalette;
  ColorIndex: LongInt;
begin

  GetMem(LogicalPalette, (SizeOf(TLogPalette) + SizeOf(TPaletteEntry) * 256));
  GetSystemPaletteEntries(Canvas.Handle, 0, 256,
    LogicalPalette^.palPalEntry[0]);
  with
 LogicalPalette^ do


  begin

    palVersion := $300;
    palNumEntries := 256;
{$R-}
    for
 ColorIndex := 10 to
 245 do

      with
 palPalEntry[ColorIndex] do

      begin

        peRed := 0;
        peGreen := 0;
        peBlue := 255 - (ColorIndex - 10);
        peFlags := PC_NOCOLLAPSE;
      end
;
  end
;
{$R+}
  BluePalette := CreatePalette(LogicalPalette^);
  FreeMem(LogicalPalette, (SizeOf(TLogPalette) + SizeOf(TPaletteEntry) * 256));
end
;

procedure
 TForm1.FormDestroy(Sender: TObject);
begin


  DeleteObject(BluePalette);
end
;

procedure
 TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;

  Shift: TShiftState; X, Y: Integer);
var


  OldPal: HPALETTE;
begin


  OldPal := SelectPalette(Canvas.Handle, BluePalette, False
);
  RealizePalette(Canvas.Handle);
  canvas.pen.color := $02000000 or
 (BlueVal * $00010000);
  canvas.pen.width := 10;
  canvas.moveto(0, 0);
  canvas.lineto(X, Y);
  SelectPalette(Canvas.Handle, OldPal, False
);
  Inc(BlueVal);

  if
 BlueVal > 255 then

    BlueVal := 0;
end
;

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