There is an active thread over on tinkering where you can change some basic color/font settings. Its not officially supported and its at your own risk. Your edits will have to be redone at each release. But it may take the edge off for you:
“Standard” roon has an unusually low contrast grey text on grey boxes on grey backgrounds specially for Classical. So there is a third color scheme many may have not noticed. Yuk. A simple change to the default higher contrast white background is not ideal but it is at least an immeasurable improvement to readability.