// it works
procedure TFGestionDesVues.sColBoxFondSelect(Sender: TObject);
begin
if TsColorBox(Sender).Itemindex = -1 then exit;
sLBoxAfficher.Color := StringToColor(TsColorBox(Sender).Items[TsColorBox(Sender).Itemindex]);
end;
…
//it does not work
procedure TFGestionDesVues.sBtnPoliceClick(Sender: TObject);
begin
if FontDialog1.Execute then
begin
sLBoxAfficher.Font := FontDialog1.Font;
end;
end;