HA Theme overwrites Dashboard specific theme

I have been using HA for a while now (no expert mind you), and I got really interested in theming certain parts of my dashboard. A custom one for my plants and power consumption. But i wanted to make them all unique, think of fonts, colors etc. But when I apply my Theme to a dahsboard it looks all fine, with the fonts. But the moment I click ‘done’ (For editing my dashboard). It reverts some of the fonts to the HA wide Theme.

After I click on ‘Done’ it reverts part of the font back to the HA wide theme. Does anyone know a fix for this? I was thinking it was fixable by adding some lines of code, but that isn’t really my strongest suit.