I am unable to change the background color of static UITableViewCells on iOS 7, when running on iPad device. You can easily check this with following setup:
just write this line
[cell setBackgroundColor:[UIColor clearColor]];
in your function before return statement
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
Because in iOS7 documentation clearly says that default color of each table cell is white. So, if you want to change it then you have to change it from your code. Remember to set the background property to clear color of your tableview from Utilities > Attributes inspector (on your right side).
hope it helps... as it worked for me...!