Colourising emphasized text in org-mode

[fatiparty]

I want to colourise emphasized text in org-mode.  Am using the following code, 
but it is not taking effect.

(defface my-org-emphasis-bold
  '((default :inherit bold)
    (((class color) (min-colors 88) (background light))
     :foreground "#a60000")
    (((class color) (min-colors 88) (background dark))
     :foreground "#ff8059"))
  "My bold emphasis for Org.")

(setq org-emphasis-alist
      '(("*" my-org-emphasis-bold)
    ("/" italic)
    ("_" underline)
    ("=" org-verbatim verbatim)
    ("~" org-code verbatim)
    ("+" (:strike-through t))))