How to select color of the Selection Tick Boxes

Hello there
I am using a DataTable setup with ‘row_selectable’ =‘multi’ (which works great!).

As soon as I change the background of my web page I can see that the column containing the selection tickboxes remain WHITE while everything else turns to the new color.

How to setup the background color for this column (and possibly the color of the tickbox itself)?

Has this column a name so that I can use conditional formatting to do that?

I saw in other forum that there is a mention of a master CSS for the library.
If I change that I should be able to achieve what I want…the point is that when I did it but I found hard to find whch element I should use.

Can you help with that?

Many thanks for this charming product