Das sieht ungefähr so aus
Delphi-Quellcode:
procedure TForm1.ComboBox1DrawItem(Control: TWinControl; Index: Integer;
Rect: TRect; State: TOwnerDrawState);
begin
if Kriterium then
Combobox1.Canvas.Font.Color := clBlue
else
Combobox1.Canvas.Font.Color := Combobox1.font.color;
Combobox1.Canvas.FillRect(rect);
combobox1.Canvas.TextOut(rect.Left,rect.Top,combobox1.Items.Strings[index])
end;