How to deal with Foundation Site Styles stack styling itself (e.g. 'dark mode')

Hi all. I’ve a question about the Site Styles stack in Foundation 6.7.3 in Rapidweaver 8.

If I change the primary text colour, that also controls the colour the site styles stack uses to display its text. So if I go for a ‘dark mode’ kind of setup (e.g. set the site style’s background to near black, then the primary text to white), the site style stack descriptions become very hard to read, as per this screenshot:

I thought perhaps the stack was using a secondary colour to style its own background, so I experimented with setting any/all of those to dark colours, but I didn’t seem to hit on one that would change the site style stack’s own background to dark so that white text would be legible.

Is there any direct way to set the site style stack’s own (swatch) background colour? Thanks much.