OK, let's change the cell border color and thickness and background colors. Unlike the table border, this has to be done individually for each cell. Although the cell border color will be the same for each cell, you may want to have a different background color for each cell, so I've left the #ffffff, which you can change to whatever color you want for each individual cell.

At the start of each section of code you will see the td data <td>:

<td style="border: 1px solid #000000; background-color: #ffffff;

Change it to this:

<td style="border: 2px solid #352ece; background-color: #ffffff (whatever color you want);

and you will see this: