Provide 'borderless-accented' modeline theme

Just a suggestion -- It could be nice to have a "borderless-accented" version of the modeline theme. I roughly recreate for modus operandi:

;; load operandi theme, then:
  (set-face-attribute 'mode-line nil
                      :box '(:color "#d0d6ff"))
  (set-face-background 'mode-line "#d0d6ff"))