All non-fixed cells of the table have this color unless the color was set explicitly by the SetCellBackColor method.
oTable.BackColor = "#ffffff" 'color setting by RGB String
sColor = oTable.BackColor 'in sColor is a RGB String in the form "#RRGGBB"
The property returns/sets the RGB String in the form "#RRGGBB".
In order to make the modification visible after write, it is necessary to call the Draw method.