procedure TForm24.Button1Click(Sender: TObject);
var
i,j,ColorR,ColorG,ColorB:integer;
ColorArea:TRect;
begin
j:=Form24.Height;
ColorR:=strToInt(Edit1.Text);
ColorG:=strToInt(Edit2.Text);
ColorB:=strToInt(Edit3.Text);
for i:=StrToInt(Edit5.Text) to StrToInt(Edit6.Text) do
begin
if Edit4.Text='R' then
ColorR:=i
else if Edit4.Text='G'then
ColorG:=i
else if Edit4.Text='B'then
ColorB:=i;
Canvas.Brush.Color:=RGB(ColorR,ColorG,ColorB);
ColorArea:=Rect(i*2,0,(i+1)*2,j);
Canvas.FillRect(ColorArea);
end;
end;