There is a growing "holy war" with tech users with "Light Mode vs Dark Mode". As a grumpy old developer of the 90's, I prefer to look at white screens when I develop code, while all the high school kids I coach in robotics, always run in dark mode. I prefer the forums in light mode, but maybe we should fit the theme of the rest of the app and go to a dark theme.
Either way, if you have some web development skills and want to take a shot and giving me a color scheme to try, I will take a look. The forums are built to be reusable with multiple apps, so the colors are all driven off a central configuration. If you "view source" on the page you can see all the colors that can be configured in the style block at the top of the page.