What you are trying to attempt in this line:
dsDataCell.Tables[Data_Sheet].Rows[RowIndex][ColumnIndex] = Color.Red;
is to change a value in a cell of "
Data_Sheet
" DataTable, which is impossible!
Note: Color.Red
returns a system-defined color that has an ARGB value of
#FFFF0000
You should rather change color of Excel cell. How?
How to: Programmatically apply color to Excel ranges - Visual Studio | Microsoft Docs[
^]
Excel.Range rng2 = excelSheet.get_Range("A1");
rng2.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);