Do we have control over background color?
You can change between a light or dark theme here.
That helps out, thanks.
I tried changing text colour experimentally using span tags, but apparently this isn’t allowed for some reason …
Just found the setting to increase text size. Handy if I’m too lazy to fetch my reading glasses, or if I am also trying to watch to tv.
Bigger text on black background works well. 
Many browsers have a “zoom” feature:
For instance chrome on windows, holding down control and using your scroll wheel will make all text/pictures (almost everything) bigger or smaller.