SuiteCRM themes are not difficult to customize if you just get stuck in. It took me a weekend of grappling with CSS (from not knowing anything about CSS) to become reasonably adept at changing things.
Like you, my eyes are not what they were and I needed something big-font, “contrasty” and compact … something that would be usable on a laptop, even in daylight. Designers will cringe, but “pretty” did not need to be part of the equation! Attached is my adaptation of Suite P.
I’m looking forward to the theme changes in 7.10, but hope there are some user-changeable theme parameters. If not, I’ll be hacking “syle.css” again!