Have you ever thought that subtle coloring of Rainbow Delimiters is not enough? Here is my solution that works quite well on dark backgrounds.
To try it, download it and install the *.el file using: M-x package-install-file
go to scratch buffer
type (((((())))))
enable rainbow-delimiters-mode M-x obvious-parentheses-colorize
if you like it you can add (obvious-parentheses-colorize) to your Emacs start-up file
Once you have tried you can remove with: M-x package-delete then select obvious-delimiters-0.11