Disable cell borders or make color (transparent)

I have been trying to see if there is a way to disable the cell border colors, making it look like a part of the page instead of an actual table.
I haven’t been successful so far, in addition I have tried all the codes for disabling the header color, but I am not sure if that is my theme or something as nothing has worked so far?

Appreciate any response.

Here’s the page

https://www.b2audio.com/1ch

The page I need help with: [log in to see the link]