Includes support for rainbow-delimeters-mode.

Naysayer is available on MELPA.

You can install naysayer-theme with: M-x package-install naysayer-theme

Then add this to your init file:

(load-theme 'naysayer t)

Download naysayer-theme.el to the directory ~/.emacs.d/themes/, then add this to your .emacs:

(add-to-list 'custom-theme-load-path "~/.emacs.d/themes/")

Now you can load the theme with: M-x load-theme RET naysayer