Make sidebar Nautilus in Arc greyish like Window colour, not dark

[Raubion]

I've been using Arc for years and I love the theme. However, what has always startled me was that the dark theme was fully dark, the darker theme was light and dark and that the regular Arc still contained some dark elements, most notably in Nautilus File Explorer.

I was recently checking out some themes and came across Enso-Gnome, of which I've added a screenshot. I really like how it is all greyish/white. I'd like to make the sidebar the same greyish colour as the window. How would I go about doing this? See screenshot of Nautilus with Arc theme to know what I mean.