Faces for emphasis and footnotes in a minor-mode

[fatiparty]

I have the following code for setting colours for emphasis and for footnotes.  
I would like to
 include this functionality to a minor-mode.  What should I do?

(defface emph-italic
  '((default :inherit italic)
    (((class color) (min-colors 88) (background dark))
     :foreground "#d166ff")
    (((class color) (min-colors 88) (background light))
     :foreground "#9e3200"))
  "Brown coloured typeface for italic emphasis.")
(setq org-emphasis-alist
      '(("/" emph-italic)) )
(with-eval-after-load 'org
  (set-face-attribute 'org-footnote nil
     :foreground "#ae6029" :background "black"
     :weight 'normal :slant 'italic :underline 'nil
     :height 0.8 :width 'expanded))