`solaire-mode' is inspired by editors who visually distinguish code-editing windows from sidebars, popups, terminals, ecetera. It changes the background of file-visiting buffers (and certain aspects of the UI) to make them easier to distinguish from other, not-so-important buffers. Praise the sun. ; Installation M-x package-install RET solaire-mode (require 'solaire-mode) (solaire-global-mode +1) And to unconditionally darken certain buffers: (add-hook 'ediff-prepare-buffer-hook #'solaire-mode)