WPF DataGrid Row Background Color depending of Last Cell of the Row

So for the better understanding. I have 2 SQL DataTables (server and client) and put them together into one DataGrid. Before i put the DataTables into the DataGrid, i added a column with a number, so that i can later see from which DataTable the row comes from. Now i wanted to change the background of the row depending of which DataTable it comes from.

My plan was:

-Use the number of the column i added at the end of the row to decide which color to use for the row.

But my problem:

• How can i get the Data of the last cell of the row in wpf?
• Can i just delete the Column after finishing this process?
• And will the Color stay, even after sorting the rows afterwards?

Sorry, but i just cant get the Data of the specific cells....

Is there maybe a better way to do all of this?

Thank you for your Help!!!!