Obviously fonts, style and theme are all very subjective. Thankfully, for anyone who wants to customize the look of a site for themselves (any site, not just fmSoup), they can turn to CSS injectors to suit their own needs.
For both Chrome and Firefox, I would recommend using Stylus, as it enables using styles from userstyles.org
Safari users have to turn to Cascadea or PageExtender. It looks like Magic CSS is the only option for Edge users.
If you are still using IE, I guess you are on your own.
If you come up with your own style(s), feel free to share with others. You can even go all out and create styles for every season or anything else you think about!