RF-tools-KiCAD VS kicad-color-schemes

If you have the time, spend a half-hour to check out the KiCad-StepUp-FreeCad RF examples. Plugin for some RF tools.. If you can get a DXF or similar 2d export of the footprint, you can feed it through StepUp->KiCad. Test it out for yourself, it will only cost you your time. All these run on Windows and Linux, support Python scripting, and use plain text files you can parse and/or manipulate directly.

I cloned https://github.com/easyw/RF-tools-KiCAD.

I don't know of any way to do it "natively" in KiCad, but the RF tools plugins includes a "solder mask expander" that should do what you want.

You are welcome. When you get used to it, I suggest to add some plugins, such as Interractive BOM, Via Stitching and RF Tools

If you mean that KiCad needs dark mode, this can be done using a combination of GTK (or QT?) color themes, which are associated with your system configuration, not KiCad, and color themes for the editing tools, which can be changed in the preferences menu. I found some reasonable options here [1], but if you're picky (like I am), you can write (or generate) your own. In the current version of KiCad, you can choose between themes (files in the appropriate directory) with a drop-down menu in the KiCad preferences, rather than editing the default configuration.

[1]: https://github.com/pointhi/kicad-color-schemes

the theme I'm using for Eeschema is behave-dark: https://github.com/pointhi/kicad-color-schemes