[*Caro*]

Hola, podrias comenzar con este truco que lo saque de trucomania
http://www.q3.nu/trucomania/

Código Delphi [-]
procedure TForm1.FormPaint(Sender: TObject);
var Row, Ht: Word ; 
begin 
      Ht := (ClientHeight + 255) div 256 ;
       for Row := 0 to 255 do
             with Canvas do 
             begin 
                Brush.Color := RGB(0, 0, Row) ;
                FillRect(Rect(0, Row * Ht, ClientWidth, (Row + 1) * Ht)) ;
             end ; 
end;