저 같은 경우는 요렇게 하니까 좀 줄은것 같기도 하고

Style->lbOwnerDrawFixed 로 놓으시고

OnDrawItem에 요렇게 함 해보시죠...

((TListBox *)Control)->Canvas->Font = ((TListBox *)Control)->Font;
    int OldBkMode = SetBkMode(((TListBox *)Control)->Canvas->Handle, TRANSPARENT);
    ((TListBox *)Control)->Canvas->TextOut(Rect.Left + 2, Rect.Top, ((TListBox *)Control)->Items->Strings[Index]);
    SetBkMode(((TListBox *)Control)->Canvas->Handle, OldBkMode);