Someone (sorry for not noting your name) suggested dimming/graying the parentheses in lisp modes and gave this elisp snippet to do it. I find that I prefer reading lisp with dimmed parentheses.
(defface paren-face '((((class color) (background dark)) (:foreground "grey20")) (((class color) (background light)) (:foreground "grey70"))) "Face used to dim parentheses.")
(add-hook 'scheme-mode-hook (lambda () (font-lock-add-keywords nil '(("(\\|)" . 'paren-face)))))
I also came across a blog post[1] which includes a slightly more complete solution.
Re:Lisp Lacks Visual Cues
by evangineer on Monday May 23, 2011 @08:40AM
(#2575736)
There's also Dave Pearson's parenface.el:
I am not experienced reading Lisp code, but I find the many levels of indentation and the abundance of parentheses overwhelming. I don’t know if this is the case with Common Lisp code.
In Chicken Scheme however, parentheses are interchangable with other brackets – so you can add visual cues through your style if you don’t care much about portability.