[[coso]]

Hola, este ejemplo usa un paintbox

Código Delphi [-]
procedure TForm1.Gradient(cl,ds : TColor; perc : double);
var
        ri,gi,bi : integer;
        rf,gf,bf : integer;
        pr,pg,pb : double;
        r,g,b    : integer;
        y : integer;
        c : TColor;
        s : string;
        wp : integer;
begin

with PaintBox1 do
begin
        ri := (cl and $FF);
        gi := (cl and $FF00) div $100;
        bi := (cl and $FF0000) div $10000;

        rf := (ds and $FF);
        gf := (ds and $FF00) div $100;
        bf := (ds and $FF0000) div $10000;

        pr := (rf - ri) / (Height/2);
        pg := (gf - gi) / (Height/2);
        pb := (bf - bi) / (Height/2);

        wp := Round(Width*perc/100);

        c := 0;
        for y := 0 to (Height div 2)  do
        begin
          r := ri + round(pr * y);
          g := gi + round(pg * y);
          b := bi + round(pb * y);

          c := RGB(r,g,b);

          Canvas.Pen.Color := c;
          Canvas.MoveTo(0,y);
          Canvas.LineTo(wp,y);
          Canvas.Moveto(0,Height-y);
          Canvas.LineTo(wp,Height - y);
        end;
        s := formatFloat('0.00%',perc);
        canvas.Brush.style := bsSolid;
        canvas.brush.color := clBlack;
        canvas.FillRect(Rect(wp,0,Width,Height));
        canvas.Brush.style := bsClear;
        canvas.Font.Color := ($00FFFFFF) xor canvas.Pixels[Width div 2,Height div 2];
        canvas.Textout((width - Canvas.Textwidth(s))div 2,(Height - Canvas.TextHeight(s)) div 2,s);
end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
        i : integer;
begin
        doublebuffered := true;
        PaintBox1.Canvas.FillRect(Rect(0,0,PaintBox1.Width,PaintBox1.Height));
        PaintBox1.Canvas.Brush.Style := bsClear;
        PaintBox1.Canvas.Font.Style := [fsBold];
        for i := 0 to 10000 do
        Gradient($00FF0000,$00FFFFFF,i/100);
       // Gradient(clGreen,clYellow,i/100);
end;

podrias crear un componente a medida poniendo eso en el evento onpaint. Vamos, que es solo un ejemplo, que se puede mejorar bastante.